Do i have a right to be angry with mom?

my daughter recently got hand foot mouth disease, which is largely a children's disease. my mom usually looks after her while i'm at work. when we came back from the doctor's that day, my mom promptly left, making it clear that she doesn't want my daughter near her. she lives with my bro and sis-in-law who is pregnant and my bro has always been her favourite over her other children. while i understand that she is concerned that she will get the disease and spread it to my sis-in-law, i find it rather upsetting that she acted that way in front of my daughter. do i have a right to be upset or angry with her or am i being over-sensitive? btw, the first thing she asked me is not about my daughter but whether she will get it or not.