grammar - Confusing syntax in sentences with indirect object complements

Some verbs produce unambiguous syntax when used with an indirect object.

    I brought a toy to Katy. --> I brought Katy a toy.

    I bought flowers for my wife. --> I bought my wife flowers.

Neither of these sentence complements can be interpreted as a single noun phrase or object complement.

But if we use a pronoun instead of a proper noun we sometimes produce ambiguous syntax.

    I brought a toy to her. --> I brought her a toy.

    I bought flowers for her. --> I bought her flowers.

The first sentence is not ambiguous because her a toy is not a sensible phrase, but her flowers is easily interpreted as a noun phrase (poss dt + n) that functions as the single direct object of the verb. Two possible interpretations with very different meanings.

Furthermore, BBC Learn English lists keep as a verb that can be used with OCi/OCd syntax but I can't seem to find a sentence that isn't ambiguous.

1. I kept the money for you. --> I kept you the money.


2. I keep the keys for the manager. --> *I keep the manager the keys.


3. I keep secrets for her. --> I keep her secrets.


4. I keep secrets for Jill --> *I keep Jill secrets.

Sentences 2 & 4 produce nonsense, and sentence 3 produces ambiguous syntax, where the OCi and OCd merge into a single noun phrase. Sentence 1 seems to work but it feels very awkward to me. But all of these sentences follow the rule of having a beneficiary or recipient of the action using to or for adverbial complement in the standard form.

So what's going on here? Does keep belong on this list or not?