What birth control options would help lighten periods?

I just bought my 13 year old sister condoms. I don’t condone her having sex but she’s doing it without condoms so I’d rather her be safe. Her periods a day late so I made her take a test and it’s negative so hopefully it was accurate. Anyway my mom won’t put her on birth control, she just says “she shouldn’t be having sex anyway” which I agree, but she is so she needs something. She’s going to tell my mom she wants to be on it for her periods being to heavy, because that’s why my mom put me on it when I was a teenager.

What birth control options would help regulate and control heavy flow periods?

She knows she wouldn’t be good at taking the pill regularly so that’s out of the question. She won’t do the Nexplanon because my sister got a breast tumor while using that (idk if that’d even help with controlling periods which is what she’ll be “needing it for”)

Edit: I’m sure I’ll be told to sit down and talk with her and I have. Since she got her first period I’ve talked to her about safe sex, abstinence, stds, periods, and pregnancy. I’ve tried. I’ve told her I’d rather her wait until she’s older because she’s still a child but she doesn’t listen to me. My mom doesn’t care enough to talk with her so idk why she wouldnt put her on birth control when she asked.

And I’ve told her that even if she’s put on birth control she needs to continue using condoms if she’s going to be having any type of sex.