Is my hair thick or thin?

So I’ve always been told that my hair is super thick by my mom and any hairdresser I go to. Anyways, today at gym class I had this pony tail that was supposed to be for “thick hair” it didn’t work very well and I took it out so my friend offered one of hers to me. I took it and said, “ Yeah this pony tail I have here doesn’t work very well” she said, “ Yeah it looks weird, no wonder” “it is supposed to be for thick hair” I laughed, “ my mom bought it for me”

Then she said, “ you have thick hair? But your hair looks thin”

“Really?” I asked, surprised by the comment

Then she was like “yeah your hair looks super thin.”

And now I’m confused because I swear my hair is thicker then hers and I’ve always been told it’s pretty thick. But now I’m wondering if it’s actually thin.

( This is a pic of my hair in a pony)

Also, I got my hair cut and thinned three months ago. Does anyone know how long it takes for thinned hair to grow back thick again??