ABANDONED. Looking for a 90's book, YA, one of a quartet

[Elana]

Hey guys, I'm looking for a book that I read AT LEAST 5 years ago. I would not put the publish date later than 2005, but I seem to remember it was a 90's book. It was young adult, and I remember reading on the back that it was one of a quartet (slight possibility for quintet, I get confused between the two words).

It was about some children - I remember there was a girl and a boy, and I think also a younger brother or sister - who were sent to the home of their family member, older cousin, I think, around Christmas time. Well, winter anyway, there was snow that I remember. The man and his "wife" met them. The woman's name was Jenny or Jessie or something in that line and she was pregnant. The children came from a very conservative household and they were very shocked a little way into the book that their (possible) cousin wasn't married to the woman, even though they were living together, nevermind the baby on the way. There was a bit of an issue about that. Then I can't remember what happened, but eventually they got snowed in, I think. And the baby started to come, but obviously they couldn't get to hospital and no doctor could reach them either. The man was running round like a fool and panicking and didn't know what to do, but then the eldest girl took charge. With her help the baby came safely and everyone was very grateful.

That's all I can remember. I hope someone can help me, and please tell me if something isn't clear! :)

[Lobstergirl, au gratin]

Elana, are you still looking for this book?

[Lobstergirl, au gratin]

No response, moving to Abandoned.