Is that the only time this woman approached your husband? If it was; he was standing and talking with another man and it's possible she thought it wouldn't be so inapproriate since he wasn't alone?

You did say that she drops her child off and waves when your husband is present, then she drives chit chat...

Is it possible that she picked your husband specifically because he "appeared" trustworthy? Also he is standing right there at the corner and not in a vehicle, which would make her feel more secure about her little one. She keeps her in the car with her otherwise if read correctly...I wasn't attempting to insult with the bathrobe comment btw.

Maybe you can walk up to her car next time and say "howdy, I'm H's wife; my husband mentioned your predicament with trying to get to work on time and if you like I could keep an eye on your lil precious" just a thought...I'm envious of y'alls poja skills btw.