School wants to suspend her over tattoos

My daughter is turning 18 in a few months and got a full arm sleeve and thigh tattoo that shows a woman topless during the holidays. Her uncle is a tattoo artist so she has really nice pieces and he’s done my sleeve. Anyways I’m checking my emails and I have one from the school saying Alyssa is suspended for a week and will need to come into school next week to figure out her suspension going forward

Yesterday she bled through her jeans and even tho I cleared her to go home they wouldn’t let her and offered basketball shorts instead. She called me saying her thigh tattoo shows so I told her to either use nipple covers on her tattoo or big bandaids, which she did! Sent me a picture and it wasn’t really noticeable just looks weird she had something on her leg. Anyways I guess her teachers reported her and said it’s too distracting even though Alyssa said no one even noticed and she kept her sweater on her lap the whole time. She had to go to office and missed 5 periods. One teacher commented how she should wear turtle neck shirts to cover her arms (we live in AZ). Ya let’s have her wearing that once it’s 115 out

I’m upset that they wouldn’t let her go home when I cleared it and now she’s being suspended. I’m thinking of going in with her next week wearing short shirt and shorts to show I don’t care about tattoos and they can shove their opinion up their ass. Does the suspension seem fair or should I bring it up with the school board?