What do you do when your family ask you money?
In my case, I often do not lend money to my family o friends, because if there are some problems with the payment, the relationship could get affected. I prefer lend an small amount of money, so I don't get worried if there are delays.
Always there are some alternatives, you could help them with something else that is not necessary money.
Saying "no", is not the end of the world. Just take your time and get confidence about your motives.