A group of us have arranged to go on holiday together. All female friends who have known each other for years. Now one of the group has asked if her 19 year old daughter can come too. Apparently the daughter had been due to go away for a couple of weeks in August with some Uni friends but it fell through for various reasons. Her mum 'feels sorry for her' because she didn't get a holiday she had been looking forward to so wants her to come along with us. Our holiday coincides with a 'reading week' from University apparently, so she will be free.
AIBU to think this is not on? She will completely change the dynamic, and none of us really even know her that well.