Bedtime for 18mth old. help

[Avo123]

Hi
My niece who is 18mths is not being put to bed until anytime between 9pm and gone 11pm.
They are first time parents , SIL 43yr , Brother 55yr.
She is so tired with bags under her eyes!
How can I get through to them what this is doing.
Of course by 6 she crying, frustrated but mum doesn't put supper on table til 730/8 (gets home 6)
They haven't changed their routine and not very organised.
All the parents I know say she would be in bed 630ish and are horrified. Do you agree ?
Myself and my mum each look after her every week to get some routine but......it breaks my heart, what damage is being done
The last weds, I got there to learn she went to bed at gone 11pm, woke at 730am because "mummy has a friend over from Australia".

How do I help get the message, I've talked about. Sent them links etc.
I feels it neglect.

I think any time is fine at 1 year, its not like they have school to go to. So whatever suits family.

However, if she's exhausted and up super early it obviously isn't working properly if she is tired and gaunt.

If they get home at 6pm then a super early bedtime is never going to suit them as they all need to eat and do bedtime. Maybe you can encourage more like 8/8.30pm bedtime? but I have no idea how you do that without offending someone.

I agree with pp if they don't get home till 6, 6:30 bed time wouldn't work.... personally I think it's for them to decide what the do and they will find what suits and little one gets older she will more than likely guide the routine anyway I have friends and there little ones don't go to bed till later either and that's just their routine.

Thks for replies
Baby is in nursery every day.
mummy could get home earlier if she went work earlier, flexible.
daddy works shifts so can take baby in mornings on those late shifts.
Supper takes 90mins to make. Baby is hanging and crying and so mummy introduced a dummy two months ago,
now being used all the time although nursery/I dont use.

In my honest opinion I'd just leave them to it, they will fall into the best routine it can't be that bad for them if they've not decided to change the routine themselves.