Isn't the sentence "My mother wishes my child were like I" more of a conditional mode rather than a subjunctive mode?
Conditional mode generally implies the impossibility of attaining the goal stated:
"If I were a rich man" (As the song says).
Whereas the subjunctive implies a will and a possibility to attain a goal. In this sense it is closer to the imperative of a verb.
Also another uncertainty here is the tense of the verb were vs. be.
"my mother wishes my child were like I" would seem to refer more to a child who already exists, whereas "my mother wishes my child be like I" could imply a child yet to be born, as well as the possibility that only if I do the right things the child will actually be like I.

The sentence as I heard it and the reason it struck me as being unusual, phonetically transcribed, was:
Whose car is it?
It is one of his GIRLZFRENDZ.
Though this is a linguistic innovation, to me it conveyed a rather precise information, namely that there are several girlfriends and the car belongs to one of them. The speaker knew the young man, his friend well enough to know that he had several girlfriends but he did not know to which one the car belonged.
I wanted to contrast this with the standard English, which as spoken cannot be precisely understood.
It is one of his girlfriends'. Or: It is one of his girlfriend's.