hello fellow mommy, it is a good thing that your baby girl is napping well & on time for milk~ for reflux, try to put your baby in a 45 degree position at least 15mins (when carrying) before laying her flat down for her nap. As for gas... no choice (sigh) have to do exercise for them everyday. my dear boy who is also 8 weeks old today, fights sleep and takes us 0.5-1hr to put him to sleep. sometimes our back hurts soooo much from 'bouncing' him. 😭
NB does sleep a lot. As long as the baby wakes up on time for milk, consistent wet diaper/poo that's good. For reflux wise that happened because baby sucked too much air or didn't burp well. Therefore the reflux. Too early to do tummy time. Until about 2 months onwards. Subject to individual babies as they have yet to learn to lift up their head. And they are still trying to learn to strengthen their neck muscles.