To make my earlier statement clearer: you cannot use the objective pronoun as the object of the preposition 'of'. 'The murder of her friend' is OK. 'Her friend's murder' is OK. 'Her murder' is OK. 'The murder of her' is not possible.
So, it applies only to 'of'?- I'm not sure. Probably only where 'of + object pronoun' is the equivalent of the possessive pronoun ( e.g. where 'of us' = 'our')
I made it for her.
I named my son after him.
I am responsible for it.
The first two are correct, the last one is wrong. Am I correct?-- The last one is wrong, but for a different reason.