Imagine that a wonderful moment of a daughter speaking to her parent about a decision like this!
Safety reasons...
is that your real concern?
Hmmm? Can share about earings...which may have similar issues.
Regular earings can have metal backs to them. When something smashes front of ear smashes that back into under earlobe. I do think thats dangerous. Really can make getting smacked in the ear worse.
Earings that snag can get torn out.
Even snag on a towel abrubtly drying hair.
I wear 5 small gold hoops in one ear.
Hoops go threw and clasp by going back inside other end. No backing.
99.98% a non issue.
...but i dont dive onto my ear.
Dont think i would want to dive on say a dragons head threaded through my navel.
I’d say if she’s going to get one, definitely do it in the off-season so it has time to heal. Not much fun sliding belly-first on a fresh piercing!! Other than that just make sure she cleans it very well with saline and wears loose clothing around it while it is healing. Tight waistbands can irritate it and cause discomfort. These piercings tend to take longer to heal than regular ear lobe piercings. Just make sure she goes to an experienced piercer who uses the appropriate sterile technique.
DD was playing basketball when she got her ears piercer. Ref told DD they had to go, I think they learned more about ear piercing then they wanted to know. DD had to tape her ears up which was fine.
DD has odds and ends on her occasionally. Some umps ask or tell her to remove them others do not care.
Personally I have not been uncomfortable with jewelry opposing players were wearing.
If you don't like or agree with it then put your foot down on the subject. If she gets her way then make sure safety precautions are taken so she doesn't end up learning the hard way why it can be an issue. If it's not a safety issue in your mind then you have a different fight on your hands.