girlfriend late replies sometimes at night.?

she's my bestfriend and she confessed she likes me 2 days ago..

we usually talk 1am and over..
but when I message her at 8.9.10 pm she takes likes 1-5 minutes to reply sometimes..

she says i cant catch up with the messages coz my friends are talking to me..


i got offended coz I feel why would u say u like me and talks about me to others if ur acting like that.. . coz I feel I'm not important.. does it have anything to do with her being really social?