Why can't I check dd1 (15) in online? Flying tomorrow

[Itchyandscratchy]

We fly to US tomorrow and I just tried to check us all in online and we got got through except her! It said she has to check in at the airport. Does anyone have any idea why this might be? She's 16 in September. (Don't know why that would be relevant though) and her passport runs out in 7 months.
I've been on the helpline for ages but it's constantly in a queue.
Please tell me this is routine! It's Thomas Cook /Condor airlines. I'm having a mild heart attack here...
Thank you

This has happened to me to when checking in my DS. Nothing to worry about.

We had this in February and, in our case, it was because her ESTA had run out. She'd got a new passport and I'd forgotten to get her a new ESTA to match the new passport number. Took me a good while to work it out.

Did you book with one airline and are flying with another? I had this with DD - bought flights from BA but flew with Air Lingus - when they transfer the flights over it doesn't differentiate between children/adults - so you can't book a child in online - young have to ring to do it.

Thanks. ESTA is all fine. I managed to get onto online chat with the airline eventually and they said there were some issues with US flights at the moment.

I'd had visions of her derogatory online tirades about Trump catching up with her. Paranoid much?!!

Lived in the USA with dcs for 4 years and I've never been able to check them in online for international travel. I always understood it was to help prevent trafficking / removing children unlawfully - just gives airport / border staff another level of checking in that they see the dcs passports at check in and get to ask them their names etc.

This happened to us 2 years ago with then 15 year old DS, DH, dd17 and I could all check in the day before flying Virgin to Las Vegas. We were told ( after a very stressful time trying to contact the agents we'd booked through and the airline) that it was to do with the agent classing a 15 yo as an adult but the airline classing home as a child. It was all ok in the end and we were all seated together.
Same thing happened on flight home.
Enjoy your holiday!