well, she wasnt making an effort for either of them to like her. she was just there for her vacation and to see if she actually like Gabriel more than just a friend. so whether she gets married or not, she still gets a vacation with her daughter in royal fashion, so win win. Also, if u read carefully, they were just friends and Gabriel was jokingly flirting until she decides to reciprocate. So it wasnt forced and they made no promises to actually tie each other down in a relationship.
Personally, I think he was mistaking close friendship for feelings because of the fact that his wife died. So basically, as Marcus pointed out, his father was not exactly thinking straight. Luckily FL was, and knew better than to just accept. Very smart woman. Glad it did work out in the end though.
Gabriel is so irresponsible!! His wife dies and then he goes force courting a younger woman, younger than his son...asks her to marry him. The he goes to take care of his late wife's sister and falls for her. Like wtf dude. What if Marcus didn't fall for Vanessa. Then won't Vanessa's efforts and her feelings will be hurt!?