@Heather1086 I'm confused about what your goal is here. In your shoes, I would either have said, "Thanks so much for letting us know. We understand that accidents happen," or just "Thanks so much for letting us know" and filed a claim later. You presumably know the age and condition of your chair, and you should be able to make a decision about whether to charge for it based on that alone, without inquiring into the details of your guest's behavior. Having a "convo" before filing a claim can't possibly do you any good. It alerts your guest to expect a bad review, etc., possibly triggering retaliation; and it puts you in the position of judging your guest's behavior and either punishing them or granting leniency based on the story they tell you. I would find that extremely off-putting, as a guest. They are your customer, not your child, and this is a business arrangement, not a teaching moment.
When I file a claim, which is rare and only if the damage is substantial and clearly not normal wear and tear, I do not warn the guest in advance. If possible I wait until after reviews have posted. I keep all correspondence completely professional and absolutely non-judgmental.
Regarding the extra cleaning, IMO this is within the normal range and you just need to build the expectation of this happening from time to time into your cleaning fee. I would not attempt to charge for it, but would leave less than five stars for cleanliness and mention in the review that cleaning required more time than usual.