Overweight infertility advice for a friend

Jessica • Just married, next on the check list... Babies!!
I am 13 weeks pregnant and this is my second pregnancy after a mc back in Oct, so I've experienced loss. I have a friend who has been trying for some time now for her first baby. She is over weight and doctors tell her she needs to get healthy and lose weight, that it may play a part in infertility. Now you and I know that it may very well be the reason, however we also know there are many women who are over weight who have no problem getting pregnant. My issue is whether or not to support the idea for her of losing weight if she hasn't done it. Her SO tells her she must not be serious about having a baby if she hasn't made the attempt to lose and weight and makes her feel it's her fault. I can see where maybe it may be her weight but what if it's not? My question is how do I support her if she's happy with her weight but having issues getting pregnant?