Was this normal for a little kid?

When I was little (2nd grade and younger) my sister used to tell me to shower with her. I asked my mom if I ‘could’ hoping she’d see I was scared and say no, but she never noticed and just said yes every time. In the shower, my sister told me I had to touch butts of tongues with her. I hated it so much but didn’t think I had a choice (she was 4 years older than me) so I did it every time. She also taught me to masturbate around this time.

Was this normal?