This happened to me. Not only was my daughter jealous of my interaction with baby, she was critical of the way I helped her with housework. She was 20 and had never lived on her own until she was pregnant. I kept trying to get along. I did tell her she'd have to get someone else. I, too, was heart broken but I stayed firm and only visited when she was there.
She applied for state assistance and entered a program which trained her for working. This program paid for child care. She couldn't find anyone that could fit her schedule. The result was that I took care of baby at my house and was.paid. I did no housework for her as I had done at her house. I was just grandma. She was less jealous and less critical as she gained confidence.
We managed this way for a couple of years until she was once again pregnant. During the time there was just one baby, we developed a working relationship so that I was able to care for both children at her house. She was again critical of the way I did houswork. I stopped doing housework. I consciously worked at not taking offense.
None of this was easy or smooth. I eventually found a way to take her comments less personally. I better understood, as Diane B suggested, that her words were much more about her than as criticism of me. I focused on being more compassionate and on other ways of feeling good about myself. Again, gradually, we both grew some more and got along better.
My oldest grandchild is nearly 15 and the next nearly 12. The last are 2 and 4. My daughter has not been jealous at all with the last 2. She has gained confidencem So have I. She wasn't much jealous of the 11 yo boy's relationship with me. We do tangle from time to time over the 14 yo girl; another challenge for me and me only because my daughter whom I adopted has mother daughter issues yet to manage. I've learned that it's not my responsibility to see that she deals with her issues. I have enough of my own to keep me busy.
I've had to learn ways to negotiate those waters. The biggest help for me is to frequently remind myself that once more what she says and does is not about me. I have had to stop doing houswork a couple of times so that I could gain perspective. When my granddaughter was 5 or so I was not welcome at their house. We worked that out.
I suggest that when you're able to let go of feeling hurt, recognizing that your daughter feels very insecure, you will feel better. Sounds like she feels that there is not enough love so that her son will love her, his father and you.
I became careful to tell her how much baby needs and wants her. I would hand baby to her before she asked for him. I see my role, in part, to show them both that there is enough love to go around. Mothers keep teaching their whole life. I taught myself ways to support my daughter in a way she could feel supported. Took me years. The pain of those years is worth eventually having a good relationship with my daughter and my grandchildren.
Both you and your daughter are in new territory. You both have new roles in a new relationship.