There are a few things to consider before allowing a 13 year old to fake tan. The first is the age of the child. While most 13 year olds are responsible enough to apply fake tan, there are some that are not. If the child is not responsible enough, it is best to not allow them to fake tan. The second thing to consider is the child's skin type. If the child has sensitive skin, they may be more susceptible to skin irritation from the fake tan. If the child does not have sensitive skin, they should be fine to fake tan. The third thing to consider is the child's skin tone. If the child has a very light skin tone, they may want to consider using a self-tanning lotion instead of a fake tan. This is because fake tans can sometimes look orange on very light skin tones. The fourth thing to consider is the child's history with sun exposure. If the child has a history of sunburns, they may want to avoid fake tanning. This is because fake tanning can sometimes make sunburns worse. Lastly, the child should be aware of the risks of fake tanning. Fake tanning can increase the risk of skin cancer. The child should be made aware of this before they fake tan.