“Shame they don’t come in your size” might work?
Could you pull her aside and ask if she’s having money problems? Say you’ve noticed she seems excessively interested in your wardrobe and it made you wonder if it was because something was going on with her finances. Offer the phone number for a local money management seminar.
Stop wearing new things to work until she (or you) retires.
If it’s more of a passive-aggressive thing, you could use some of the snubs recommended above. But if she means it sincerely, you should accept the compliment gracefully and move on.
We’re in a similar situation. We probably earn around the same but I don’t have children and my husband is in a higher income bracket than hers. I never considered the possibility that it could be some kind of money issue but maybe in an innocent way it is. Maybe since she is not used to getting new things for herself often, she is taking more notice when she sees someone else do it.
Thanks for all the good tips everyone. I will try out some of the more subtle ones at first and then if I need to (because subtlety is not her forte) I might try a direct approach.