hi INshadows and welcome to the forum.
this is a sad story no matter how I look at it.
The biggest thing is
you're just kids.
There's so much more in this world
than worrying about a drunk sister.
I lived that one, too - and at about the same age.
I'm glad you're here.
I really am.
I go no answers
nothing for overnight anyway.
But it may well be time to start looking for another smaller place
that's only big enough for you.
It would remove the 'stayover' option
and be something you can afford for yourself.
Maybe just a casual thing to start doing on your own
sort of a private 'hope chest' thing for your own peace of mind.
I encourage you to look for and attend any alanon meetings
that might be near you.
sometimes hospitals offer 'support groups'
in areas where alanon isn't active.
I'm glad you're here.
there's a lot of people on this forum
that know what you're dealing with
and want to offer their support to you.
Welcome!