I haven't been in either characters shoes before as a straight white male, but I could see why Maggie got scared. It must feel like a lot of responsibility to be the reason someone changes their whole life. To be why they put themselves into a very open target. She must have felt very afraid of hurting Alex is she did things wrong. But Alex was a strong woman who didn't make decisions lightly and I think Maggie saw that and realized if she friend zoned Alex for to long, Alex would explore her new life elsewhere