how to console a 10 year old who is all teary eyed and sulky at you being late to pick them up at school?

[Mumsfan]

l had already apologised, told her that the teacher told me it was 1555 not 1520, once back home, she slammed the door shut. l went in her room and demanded she apologise for slamming the door, she at first said l didnt apologise to her, l did, so repeated it again, sincerely, she slurs out an 'apology' with no eye contact. later l go in room to tell her some good news, she tells me to just go away. should l just let her sulk and wait for her to get over it or speak to her?

Give her not of time, and then offer a snack or drink she likes. explain it was a misunderstanding
and then talk about anything but don’t dwell on the way being late

School finish times havent changed in decades. I'd be angry too.

thanks for advice all, things are fine now :)