In theory, adding two more females should alleviate the problem. However, you're really overstocked in your 10g and 29g already so adding more fish will only worsern the problems. Can you rehome some of them or upgrade your tanks? If not, you could try adding more hiding places for her. Hopefully someone will come along with some other suggestions.
I would try adding 1 to 2 more females. This maybe wrong, I have heard that if a male is so attached to 1 female he will not even act like he see the new females. So you have to remove him for a couple of days. Like I said before, it maybe wrong.
I agree that adding a few more females (similar sized, important) should at least divert his attention somewhat. However, I strongly suggest against putting any more fish in your tank until you move some out. Moving the mollys to a larger tank would be ideal. Most people recommend 20g minimum tank for mollys because they get up to 3 inches easily. Best of luck!