Everything will be okay. This is completely normal and there's no need to be scared or nervous at all.
"Yes, kind of. Millie should say it."
*Explains her problem*
“Hi girls, is there a problem?”
“Millie, Lydia is right. You are experiencing your first period. “Menstruation” is the proper term for your period. A menstruation cycle usually lasts 5 days every month. Most girls usually use a pad and/or tampon, since you’ve only begun yours, I would say to use a pad. During your period, you face a lot of symptoms like mood swings, where your mood changes rapidly. Irritability is also common, meaning that you feel angry or annoyed easier than you usually do or for no reason."
“You may also have experienced breast tenderness, where you feel a sharp pain or aching in your breasts. Cramps another type of physical pain you’ll feel, it’s just pain in your stomach; I’d say it’s pretty similar to a stomachache. Throughout puberty, acne and pimples are inevitable. When you go home, I highly suggest that you tell your mum and go into more detail since I’ve only told you some of the things you need to know. Alright, I will give you some pads.”
This makes a lot of sense. I'll talk about this with my mum when I get home.
"Go into the bathroom and put the pad on you underwear, it should be quite self-explanatory"
"Thank you for telling Millie to come see me, if she was misinformed or didn't do anything about her period, something bad may have happened.