Need advice about my son's nana

WMDCFG

My son's nana sent me a slightly nasty e-mail about how my son's father is struggling financially but I am separated with my son's father because he broke the rules for the second time and dealt with the police again. It was slight discriminatory and I felt the e-mail was more about her son than it is of my son and I feel I am out of the picture. She seemed judgmental and asking for too much like she makes decisions and rulings of my family of my son and I and my son's father. She sent me from saying if I don't make a decision then she will hire a best lawyer to when can we visit. I need to reply back to her and I do not know how. Especially my grandma is in her death bed and this is making my stress a lot worst. Please help!