Mom's not crazy, she's just being careful and apparently your little fellow really impressed her. I have a friend that helps place people and dogs together. Whenever she runs across a small litter that she knows she can find good homes for, she gets as many as she can! She knows she can always find them a good home. If one really strikes her fancy, she keeps it (not very often though). Mom will realize that 3 pups are quite a handful and narrow it down pretty soon I think. I'm glad she found a baby so quickly and that you are both happy!
Peace and God Bless,
Windy