Sounds like she very well could be jealous, but not necessarily in a hateful, ugly way. If she truly thought she couldn't breastfeed, and that's why she quit, she may have sever guilt/inadequacy issues as a result. I had a coworker tell me it broke her heart that her breastfeeding relationship with LO didn't work out and that it was really, really hard for her to be around bf'ing moms for awhile because of it. Once she dealt with her feelings and realized that not bf'ing her LO didn't make her any less of a wonderful mommy, she became more and more comfortable both a)being around bf'ing and b)talking about it. I would just suggest you be sensitive to her feelings (e.g. instead of saying 'breast is best' to another expectant mom, you can inform them that you bf and let them know you're there with advice and for q's) but do not feel like you have to slink around when going to pump. You're doing what you feel is best for your LO just like she did.