Ohhhhh. Furniture can be a sticky subject with older people i.e. moms. I know it's not a good scientific sample but my moms goes crazy for the "good" old school furniture. I'm not sure if it's the attachment to the actual pieces and the memory, or her thinking that something is more valuable than it is because she paid alot for it in 1962.
When she moved from Chicago to San Diego she insisted on bringing many pieces of crap that cost three times the actual value of the stuff to move across the country. Only a few though, to her credit, she got down to almost nothing from being a near hoarder. One of the boxes contained these lace curtains that would practically fall apart when you touched them. They were sun damaged and coated with dust. I think they were custom made for the windows in the 60's. In her mind, no matter the true state of the curtains, they were good, expensive curtains that must be saved at any cost.
Not that this is the case with your mom, but, furniture isn't as big of a deal to younger generations. We have Ikea and furniture warehouses all over the place. Passing down furniture just isn't something you really do anymore. Good luck dealing with moms. Maybe if you just apologize and go straight into the rough time you're having she'll go a little easier on you. Or, if you want a better gamelive story, give your mom Marla's number and the okay to call the cops about the "stolen" furniture.