6 year old figured out my Netflix password and won't stop watching YouTube

Found out yesterday my kid has been sneaking on YouTube at night after we think she's asleep and watching who knows what. I changed my passwords and set up parental controls but she's already asking if she can have her own tablet for school. I know the other kids have them. Are tablets really necessary at this age or am I being too strict? I just don't want her going down some weird rabbit hole of inappropriate stuff.