Sorry if it came across rude, our baby is very close to being born and I feel her anxiety. I won't be getting vaccinated while I breastfeed. My husband has been super supportive of all my decisions though. At the end of the day, this baby is my life, I've been caring for it for 9 months, I've worried about the movements, or lack of, I've worried about cramps, discharge, I've felt the feet in my ribcage, the use of my bladder as a squeeze toy. I've not drank caffeine, alcohol, I've avoided smokers, I've done everything I can for the past 9 months to protect this baby. When this baby is born, it'll be harder to protect them, I'll have to trust other people with them, it's scary. I would feel even more anxious if I felt like people were trying to pressure me to do things I wasn't comfortable with. I really think you should just support her, her anxiety will be less if she feels like she has control and like you'll back her up.
Also, can you imagine if you convince her to allow it. And she catches covid, and is ill, while having just given birth and having a new baby to look after? You'd feel so guilty, and she'd feel resentful.
It might not be 2 months, she might decide she's comfortable with it in 2 weeks. But she will always resent being pressured. Just focus on her and your baby right now, looking after them, helping her, they're your priority.