Those blue eyes are so hard to resist, I can totally understand the temtation to keep her. Either way, you will make sure she gets a very good home, with you or with someone else.
She certainly looks very good now, and seems like she's very happy with you! You've done a great job taking care of her and her babies. Whether you decide to keep her, or find a great home for her, I'm sure she can trust that you'll do what's best for her.