6YO niece rather boisterous around my now 14MO daughter. Last family visit she was told off several times for deliberately throwing Duplo blocks at my child, bouncing a huge beach ball off my child's head whilst my daughter was eating her lunch etc. She also deliberately wiped food on my partner, I assume just for some attention. Several family members have commented in the past that her attention seeking behaviour may be linked to childcare arrangements being a bit haphazard and she spends a lot of time at her grandparents and at other carers. Her father does not live with her either. Whether any of these factors affect her behaviour in that way, I don't really know, but I am dreading their next visit as I cannot leave my niece and my daughter in the same room without me being there, so making drinks for parents, cooking etc is really, really difficult even though my partner is there trying to mitigate disaster at all times!
My parents don't do anything, even when the other niece (niece 1's sister) who is under a year old falls over and bangs her head, or when niece 1 picks up niece 2 roughly and plops her down so that she bags her head, so I can't trust them to stop accidents involving my own daughter. I have asked niece 1 to be gentle and have several times specifically asked her to stop doing something to my daughter, or too close to her, but she just finds something else to do that is potentially harmful to my baby. My sister doesn't always come with them but last time she was there and she did tell niece 1 off when she saw her do something, but sometimes, what I consider to be unacceptable behaviour around babies is ignored or somehow not seen. I tried to engage niece in conversation and we even managed a bit of play although getting her to play gently with my daughter wasn't possible. She is a very nice little girl when she has full attention from an adult, but it is very difficult to play with her all the time when I have my own 1YO demanding attention. My partner ends up doing a lot of entertaining of niece in order that she does not do something potentially harmful to our daughter but this isn't 100% successful either.
I suppose I ought to start with talking to sister about what is going to hapen next time they come... but I would like some advice please.