What's this book I read as a tweenager?

[CandleQueen]

Set in America, New Orleans-ish I think.
Girl meets a strange family.
The boy is called Gabe. He has siblings.
It turns out he is/they are immortal (maybe vampiric, but I'm not 100% sure).

I borrowed it from the library around 1990 - 1994, but of course it could be older than that.
Any ideas?

Bit vague is it?

Sounds like the predecessor to Twilight LOL

I'm reading New Moon now (read Twilight last weekend!) and it got me thinking about this book.

I can't for the life of me remember what it is called or who it is by but I am pretty sure I read the same book. The family don't age, right? So they have to move around a lot. One of the siblings is a teenage girl? It's a young adult fiction novel.

Sorry that's not much help is it!

That's sound about right Thingibob!

It's really annoying, because I haven't even got enough info to Google!!

No, this is familiar, it's not an Anne Rice is it?

Having googled- I don't think it is. Though I do think I've read it.

We're not just doing this to annoy you, promise!

Locked in Time!
Lois Duncan

Gabe, sister Josie, mother Lisette!!!

Here!

That's the one!

Did it just come to you? As soon as I read the title I thought I can't believe I forgot that. I read it quite a few times I recall.

I tried some more through Googling! I then remembered the name Lisette too.
I've just tried to see if the local library service still has copies, but alas no.
It might have to be an Amazon purchase!!