S.H.
your picking her up/rocking her, probably enabled her to get out some built up gas.
Gas pain hurts.
My daughter was like that. She had lots of gas pain and rarely burped or farted. We used infant gas drops for her which helped a lot.
But babies wake. They just do. And there are not always reasons for it... they are developing in so many ways... that they get tweaked.
Also be sure to feed on demand.... so her growth-spurt needs/intake is keeping pace with her growth. You said that for the past 3-4 weeks (that would have made her 9 months old)... and this was a growth-spurt time. So... it may be that she is just hungry... and her intake needs has increased... but is not keeping pace with her increased intake needs. Thus, she may be waking because of hunger.
Every 3 months... is a growth-spurt time in a baby. For the 1st year especially... it is important to feed on demand, for these reasons.
all the best,
Susan