Couldn't she just give them the doll?

SPOILERS ahead...





Sounds crazy today, but that would've been too immoral for the character. The worst Mike does is yell at her for the doll and when she wouldn't do that, he respected her strength and they parted almost as friends. Richard Crenna's Mike character talked tough and carried a knife but many criminals back then had a code against hurting women and children. Mrs. Hendricks couldn't expect a character as violent as Mr. Roat to show up later.

She planned to until Gloria phoned with their secret code and she realized that Mike was in on the scam that Roat and Carlino. She knew that if she gave Mike the doll she and Sam were as good as dead. She figured out that Roat killed that doll woman (Lisa) and that he was dangerous.