Why is she wearing that outfit though
isn't that the clay season one?
I suspect she has a fairly basic sponsor deal with Wilson. Not a lot more than bespoke racquets + free clothing and a (too) small check.
Wilson doesn't do much in clothing compared to the giants. I guess the focus in on the ball striking equipment. So they probably dont care if she wear the older stuff.
Personally I think she could be playing in a bin liner and still look the part.