From the OP, it would appear that the source of frustration was that the no-doubt sincere apologies of the cabin crew were followed up by Customer Relations with a response that basically said “Our investigation shows there was no problem.”

It’s not clear whether this was a response to a follow up by the OP after the flight, or simply a response to the report filed by the CSD. Either way, the implication is that the OP, or CSD, or both, were telling tales.

Which is unfortunate as this seems like one of those situations where a genuine, well-worded response from Customer Relations that said “mea culpa, thank you for bringing this to our attention so we can ensure it doesn’t happen again, we are pleased your mother did not suffer any serious injury and we’re truly sorry this happened” could have easily resolved this.