Use of "le, la, les.." vs. possessive pronouns: "son, sa, ses..."

Question

I have noticed that all the phrases use the pronouns, "le or la". As in:

"La fille dont le frere travaillait avec moi..."

"Francois, dont j'ai rencontre la femme..."

Is there any problem with saying the following for example?:

"La fille, dont son frere travaillait avec moi, a gagne le prix"

"La femme, dont son fils j'ai rencontre la semaine derniere..."

"Amelie, dont ses enfants sont venus chez nous, sont bien eleves"

Accepted Answer

Answering my own question:
After reading over my question again, I suspect that the use of "son, sa, ses" would be redundant, because "dont" in this case means, "whose" and therefore there is no need to use the possessive pronouns. It also sounds rather awkward to my ears. But, just wanted to clarify.
As usual, thank you for your feedback.

Answer

Yes, it would sound redundant.