As an update I'll say that although she still has had some issues with her clothing the challenges are different since she's pregnant.
Aha! Congratulations to her and her husband!
Well, perhaps that explains the clothes being too tight. Perhaps she has been trying to squeeze into clothes from before her first pregnancy? It is hard to make adjustments when your body is changing so rapidly.
I think you are a wonderful colleague for thinking about helping her. She MUST acquire some clothes that fit properly. Since you like her, then take her under your wing and do whatever you can to help.