You are absolutely entitled to feel sad and sorry that your daughter has entered this phase that is confusing and painful for them.
My daughter had her first aged 7. It was a shock! Gp referred us to the hospital, where she was examined naked - she didn't mind, she was still a child. BUT with developing breasts etc and they put her at stage 2 of puberty.
I'll never forget because they were doing blood tests, stimulating the pituatry gland (?) I think. So we were in the children's ward all day, because they were taking tests every couple of hours.
At 7 it was much easier than 9 would have been. She asked a 5 year old what she was in for, her mum said broken arm, mine said - I've got the early puberty! 😭 Of course it broke my heart a little and made me feel sad.
They said she wouldn't have even been seen if she was 8.
To those saying sanitary pads are easy - in essence yes, but it's the knowledge of leaking, when to go to the toilet, being ALLOWED to go to the toilet and just how new and horrible it is to a youngster.
I understand @KelmenaBallerina also, I'd still put a pad in period pants. My daughter is very heavy but is mid teens now. It was difficult introducing her to tampons and that was when she was about 12.
You'll do your best I know. It's what us Mums do. I am going to send you hugs. You both deserve them xx
Ps my daughter missed some days of secondary when her flow and cramps were too heavy. I didn't give a shit what the school said, she is my main priority. Lots of love.