What is the name of this romance book?

Set in the US about a female attorney whose husband and 2 small childaren are killed in a plane crash that she was supposed to be on. Someone hires a killer to get rid of her, instead they go on the run together trying to find out who wants her dead, end up taking her Mum's dog with them (Bull Mastiff). And end up in a relationship. Some of it is set in the mountains - snow.