I’ve name changed for this.
About two years ago my friend was having a clear out and asked me if I wanted a bag. She hated it but I really liked it. I use it lots and have been given loads of compliments on it.
A woman I work with is really into bags (mulberry, Pravda etc) and was always going on at me that she thought the bag was worth a lot of money because she thought it was real ostrich skin 
I never paid heed to her but my mum commented recently that she had looked at the bag and she was convinced it was real ostrich.
Cut a long story short and the bag has been checked and valued and it’s real and worth thousands.
I have absolutely no plans to sell it. My friend bought it at a market abroad and thought it was a fake.
Do I tell her it’s real? Do I keep schtum?