Yesterday!

I spent most of yesterday, Sunday, feeling rather rotten - cold - oh, so cold. I had pretty well decided that I could not go to a late afternoon party at Barb's - but about four I realized that I felt just fine and the sense of freezing had ended so I hopped through the shower and headed to Barb's.
It was great! All four of her kids were there - one from Hawaii, one from South Carolina, one from Roseville and one from next door. Anyhow, I got to know all those kids when they were much younger - like twenties and early thirties and Sonja, who was 13. My kids can grow up but it is always such a shock to see hers so grown up. So we sat on the deck and talked and talked. There were four other outsiders there plus assorted spouses and children belonging to Barb' kids. Her next door dwelling son, Lance, bar-b-qued hamburgers for all and Barb and her girls prepared all the fixings - so it was a casual but very good supper. Anyhow, I came home with the great feeling that I was glad I hadn't missed being there.
Question - is "hers" correct or should it be "her's"?