For starters, don't say
Sorry! ...For seconds, don't say
Sorry and also don't say
Sorry! .... Have you caught on yet?...And why are you even going to apologise for her mistake?
All you need to do is tell her, it was too late but you would of loved to go. Also you now have her phone number so I'm thinking it would be even better to get onto the phone and either text her or phone her being playful about it.
'Heyyy missy... I had to go out the other night and I missed your late invitation reply to the concert , Damm, It would have been good as well"
I reckon she'll reply with a sorry and you then translate into going or doing something else together!
