[quote=@Estylwen]
Whoops! I imagine Cosette to be about 17 in The Dark Beyond, which would make her 10 in Adventures in Candyland. Is there anyway that could possibly work? :)
[/quote]
That [i]could[/i] work, but then Nick isn't 'younger than his kids', so in this case he would maybe be younger than his two oldest kids. [i] IF[/i] Lexi is okay with that, then we have option 3. 

Sabrina is 38
Oldest is 18, not by Sabrina, and 25 in DB (older than Nick)
Middle is 17, Sabrina's oldest, gotten when she was 23, 24 in DB (older than Nick)
Cosette is 10, Sabrina's youngest, 17 in DB (younger than Nick)

That's a big gap between her two kids, though. The gap between oldest and middle doesn't matter though, because different mother/unplanned.

However, getting her first kid later is prob more realistic for Sabrina too, who also focused on her career.