A tola is a unit that is used to measure small weights in some countries, like India and Pakistan. It's kind of like a big pinch of salt or sugar.
When someone says something weighs a tola, it means that it weighs about 11.7 grams, which is about the weight of two teaspoons of sugar.
People use tolas mostly for measuring precious metals like gold and silver because they are expensive and small amounts can be worth a lot of money.
So, if your mom says she has a piece of jewelry that weighs two tolas, you know it's not very heavy but it's still pretty valuable!