I've asked a woman to marry me who has 3 kids!

Okay....okay......I met a fantastic woman two years ago.....she has 3 kids...yep-15, 13 and 10....I love em but I hate 'em.....they break stuff and make everything around them filthy.....I am 46 yo and I make a very nice living.......ever since I proposed, I can't help but feel as though I have f'ed up......I want to do the right thing......help me!