How to make my facebook profile secure?

[smackaroodle]

So I thought that I had everything blocked from anyone who wasnt my friend. Like they couldnt see my pictures, or my videos. Then today my mom was on her account and because she has 3 mutual friends with me she can see my pics and vids even tho im not her friend. How can i change this? I really dont want her to see all my stuff...then i clicked preview my profile and facebook says that ppl who are not my friend will not see it..i am upset please help
i think i may have come across the wrong way i dont do things she wouldnt approve of..thats not at all i just dont want her to see everything