Just keep an eye on the level in your coolant overflow resovoir, top it off accordingly and it's not a big deal. You're not in any danger of overheating it if the leak doesn't get so big you can't keep up with topping it off. Merchant's was just trying to upsell and let you know what was going on with your car, they're probably getting pretty slow.

Get the water pump/timing belt service done when you can afford it, it's good to get done anyway. I'm pretty sure it's reccomended as a 60k service from the dealer. And if your parents own the car try and get them to pay for it and take it to the best place to get it done in most cases, the dealer.