Advise needed!

[Beautifulbella]

My lo is 6months old, her father has been in and out of her life since her birth. Sometimes he lives with me then randomly decides that he longer wants to and goes back to his parents house. He manages to see his daughter once a week only if he can get a lift. Me and oh mum are not on good terms at all, this is down to her behaviour towards my lo. We had a fantastic relationship until she become absent in my daughters life although we live ten mins away, when I ask her why it's like this, she wants crazy and was quiet aggressive. I have since said I do not want to be near her. My oh wants to take my lo to his sister house for the day, they live in a different county and his mum and brothers will be there. I'm not sure I feel comfortable with this. One reason being she hardly knows her dad, secondly she hasn't seen that family since she was a newborn so for sure will not have a clue who they are. I asked for the address and was told I couldn't have it. But my lo is so demanding I'm worried they won't know how to cope with her, I don't want to come across as if I'm doing this to point score which I'm certainly not have you got any solutions or advise please? Thanks