Is it permissible to buy jewelry during the Three Weeks?

Hello, esteemed Rabbi. I would like to buy a piece of jewelry for my mother's birthday. I won't be able to purchase it by next week, and this Sunday is the 17th of Tamuz. The store is located in Jerusalem, and I need to travel specifically for this. I am concerned that the jewelry may no longer be available in a month. It is a special piece that she has wanted for a long time, and I want to make her happy. Is it permissible for me to buy it during the Three Weeks and give it to her during this time? How should I proceed? Thank you very much.