Personally, I wouldn't... It's up to the agent to interpret whether you're trying to pull a DYKWIA and it may backfire on you.

I would imagine that the compensation is tied to your mother not having status on UA, but I certainly would state what was offered at the gate, and perhaps highlighting the INVOL part of it in case the agent missed that part.

The lesson here is that any compensation offered at the gate must be taken at the gate, and that after service recovery may not be the same offer, as the GAs have far more leeway in their offers in order to resolve a situation right then and there, and you avoid the he-said-she-said scenario.

Good luck.