My stepdaughter was experiencing a similar phenomena for a while (intrusive thoughts, zoning out, memory lapses). She did a quiz online and decided she had schizophrenia (!) which we really didn’t agree with but we started keeping a symptom diary and after about 6 months had a tonic clinic seizure, so went to A&E.
She was referred to a neurologist and while waiting had a second TC seizure so that sped up the wait a bit.
After various tests and scans she was diagnosed with epilepsy and is now on some quite heavy duty medications. She was almost 16 when the tonic clinic happened and apparently it’s not uncommon for girls to develop epilepsy at adolescence.
The ‘zoning out’ thing turned out to be Absence seizures: https://epilepsysociety.org.uk/about-epilepsy/epileptic-seizures/absence-seizures
Apparently starting with small symptoms that build up to a more obvious seizure is a common pattern in adolescents who develop epilepsy:
https://www.epilepsy.com/what-is-epilepsy/syndromes/juvenile-absence-epilepsy
I’d suggest requesting a referral and keeping a symptom diary - if she seems to be acting strangely or has an obvious seizure, make a video (I know, it feels like a terrible thing to be doing when a child has a seizure but the doctors really get a lot of useful info out of video evidence)
I don’t know if your daughter is interested in caffeinated drinks but it’s best to avoid them if you suspect epilepsy - I’m pretty sure my stepdaughter’s initial problems kicked off when she started drinking that awful Monster stuff, which is very trendy in her friend group (caffeine doesn’t cause epilepsy but it does seem to be connected with triggering seizures in some people https://www.epilepsy.com/connect/forum-archive/living-epilepsy-adults/epilepsy-and-energy-drinks-think-you-drink)
Hope you find some answers for your daughter’s struggles - we had no experience or knowledge about epilepsy before the Tonic Clonic so you are way ahead of us in that regard!