Maria, I tell people to stir, GENTLY, with a sanitised spoon, but in all reality, if you siphon onto the hot sugar-water, and get a little whirlpool action going, you'll be fine.
Besides, if you get some bottles with a double-strength dose of sugar, it will just be a gusher, not blow up. (It'll be overcarbonated, but not to the point the bottles explode.)(Provided you are using good bottles.)
Oh, welcome to the Forums, and also to Homebrewing!