Last week's episode of Supergirl, 'Far From The Tree', was split into two very distinct storylines; one featuring Supergirl (Melissa Benoist) herself, and the other focusing on her sister, Alex (Chyler Leigh). While the super-team was busy off-world, Alex continued to plan her wedding to Maggie (Floriana Lima). The two had a wedding shower, and Alex encouraged her fiancee to try and patch things up with the family that kicked her out when she came out as a lesbian. In an incredibly emotional storyline, Maggie's father comes to visit... and leaves again, furious with his daughter. Like most of Alex and Maggie's story so far, the episode was complex and very well-handled. 'Far From The Tree' did more than just reveal a little more of Maggie's past, though.The episode also started to set up Maggie's eventual exit later this season; something that was continued this week in 'The Faithful'. This episode continues to show the major issue in Alex and Maggie's relationship, as Samantha's (Odette Annable) new job puts pressure on her relationship with her daughter. Supergirl was back for a girl's night this week, and the episode ended with Alex confessing to her sister that she knows she has to break up with Maggie, even though she loves her 'so much it hurts'.

A Sanvers Wedding In The Works

Maggie and Alex's wedding shower in Supernatural

Maggie has been a part of Supergirl since the start of season 2, when she met Alex working for the National City Police Department (NCPD). Their relationship slowly developed into a friendship, and blossomed into love as Alex came to realize that she was gay. Although they had their ups and downs, like any relationship, when Alex proposed to Maggie, she immediately said yes. Season 3 sees the two of them are planning their wedding, and this week's bridal shower was another milestone moment for Sanvers (the fandom's name for the couple).

This relationship is a huge one for Supergirl, and the build up to the wedding is huge. While Supergirl herself is still single and mourning the loss of Mon-El (Chris Wood), as is Jimmy Olsen (Mehcad Brooks) and while Winn (Jeremy Jordan) does have a girlfriend, she isn't a big part of Supergirl. The Sanvers romance is the big one for Supergirl, and knowing that it won't make it to the wedding is heartbreaking for many fans.

Maggie And Alex Can't Agree On Children

Supergirl Crossfire Alex Danvers Maggie Sawyer

The issue of parenthood is one that has been brought up before, and Alex and Maggie talked about it again on 'Far From The Tree', especially as Maggie's relationship with her father is such a big part of the episode. While Alex would love to have a family with Maggie, Maggie simply doesn't want to have children; a difference of opinion that is going to have major repercussions for the pair. In 'Far From The Tree', Alex admitted that she had hoped a reconciliation with her father might make Maggie change her mind about becoming a parent herself; a plan that clearly backfired when Maggie and Oscar didn't reconcile. At the end of the episode, Maggie reiterates that while she loves Alex and wants to plan a life together, that's just not a life that involves kids. Alex, for the second time, pretends that this is ok by her, but it's clear that that isn't the case. After all, she has already attempted to manipulate Maggie into changing her mind once, and it's unlikely that she is going to let this go.

Nor should she. The desire to have children, or the decision not to, is a huge one. It's something that can easily be the end of a wonderful relationship, and it would be a fitting reason for Maggie (or Alex) to call off the wedding. The breakup has been described as "a story that we really feel like honors what's come before them, and honors how much they love each other, how much they mean to each other, and how much they've changed each other's lives. It's some of the most emotional stuff we've ever done", and a disagreement over children would fit that perfectly. If Alex feels that she needs children in her future, she cannot force or manipulate Maggie into having them, and if Maggie just doesn't want to be a parent, she can't expect Alex to give up that dream for her.

The Moment That Alex Realized She Has To Leave Maggie

This week, in 'The Faithful', the issue of children was brought up again, as Samantha's relationship with her daughter was front and center for the episode. Kara invites Samantha to a girls' night at her home, where she is chatting about being a single Mom. Alex is obviously blown away that Samantha can do so much, and when Samantha replies that Alex and Maggie will find out for themselves when they have kids, things get a little awkward. Alex tells her that they have decided not to have children, and everything seems fine (in fact, it shows just how that kind of mistake should be dealt with), but her face gives away a little too much sadness at the idea.

Later, the girls show up to Ruby's (Emma Tremblay) school show to support their new friend, and this is the moment that breaks Alex's resolve. First, an adorable troupe of girls do a dance inspired by Supergirl, and then Ruby gets up to sing a song. At this point, Alex leaves the gym, near tears, and when Kara follows, she breaks down. In a heartbreaking scene, Alex confesses that she does want kids, that she wants to be a Mom, and that she knows Maggie won't change her mind on that. She loves her fiancee, but this is just a dealbreaker for her, and she sobs as she asks her sister what she should do.

How Long Will Maggie Stay?

It was announced back in May that Floriana Lima would be stepping down as a season regular, but at the moment, it hasn't been officially announced when the actress will be leaving Supergirl. A photo from episode 5, 'Damage', shows Maggie and Alex still seemingly together, so we can assume that the breakup won't come before then. However, with the issue of children having come up multiple times at this point, the wedding plans in full swing, and Alex realiziung that she does want a family, things are going to come to a head very soon. The synopsis for 'Damage', that Lena Luthor (Katie McGrath) is accused of being responsible for children getting lead poisoning, may hint that the topic of children arises in this relationship again... and the synopsis for the following episode includes Alex and Kara heading home 'for R&R'.

Could 'Damage' be the episode that marks the end of Sanvers, followed by some time at home to recover from the breakup? This would make a lot of sense, as Mrs Danvers (Helen Slater) also showed up in 'Far From The Tree' as a loving mother; when Alex and Maggie do break up, it's very likely that Alex heads home to see her mom. Of course, Sanvers may carry on a little beyond this (and the fallout from the breakup is sure to impact Alex all season), but it seems like this relationship is set to end in the next couple of weeks.

Supergirl season 3 continues with Damage' next Monday at 8pm on The CW.

Next: Alex Danvers, Coming Out, And Supergirl's Quiet Revolution