Three Secrets (1999)

When a family of three who are in a plane flying over the mountains crashes. The parents are killed but their 8 year old son is still alive. Later it's mentioned on the news that it's the boy's birthday and that he was adopted. That's when three women who all gave birth to a boy on the same day and gave their baby up for adoption, wonder if the baby is their's so they all go to where the crash occurred and wait to see if the boy is found. They all get together all learn that the adoption was handled by the same lawyer. So they contact her asking her whose child is the boy.