Am I being petty by wanting my mum to accept outside assistance for going to bed, a few nights a week? It means going to bed earlier.

My mum has end stage heart failure, I live with her, my dad and my 3 daughters. I was doing all her care but we have been granted some low cost care. One thing they will do is assist mum to go to bed. However mum likes to choose when she goes to bed - between 10pm and midnight... Now for the last 6 months I have assisted her every night - trying to get her to go earlier so I am not so tired. Thats why sometimes she goes at 10, as prior, she would stay up till after midnight every night. The low cost carers, only come at 8.30pm. Now, mum has a TV in her room, and a comfy setup. There is no reason she could not get the assistance to get in to bed, and just stay up IN bed (as she does during the day sometimes). But she refuses - and dad supports her in this... They say its not right that she should be 'forced' to go to bed early. I eventually got upset about this and tried to leave dad to do the bed routine (which he had observed and concluded he could easily do)... Of course I make it LOOK easy, because its care work, and you are trying to make someone comfortable and keep them from getting too sick. But each night mum would get very sick due to them not coping with dad doing the bed routine, and he would have to come get me to do it anyway. I thought this may get them to realise that it IS an effort. And I want some nights to look forward to when my own evening is not dictated by my mum... I get tired, I cant wind down till after she is in bed, I cant make plans to go out... nothing. But according to mum AND dad, mums right to choose her bedtime is paramount. Its so minor in the scheme of things, but I feel a bit bitter about it. So am I choosing a petty battle, or should I find a way to explain that it would be nice to have some evenings that didn't revolve around mums choice of bedtime?