First, congrats on your new buddy!
Second, in such a small amount of water you need to do 100% water changes about every other day. I would take out any ornaments as the fish needs every bit of water possible in such a small tank.
Next, you need (as best you can) to make sure they are staying warm. You don't want them getting cold at night and hot during the day. Even temps are best. Can mom spring for a thermometer? You can get them for less than $3 most places.
What brand of food did you get? How much are you feeding? Cloudy water could be she is overfeeding hers.
We will help you till you get a little bigger tank.