Ah, my girl was 2.9 lb when I first brought her home

I fed her in small amounts about 3 times a day. I would look at the feed recommendation on the can/bag as it'll tell you how much they should have in one day based on weight and from that you'll split that into 3 meals. Hmm yours sounds like on the slightly smaller side? Or average at least. A puppy weight website I checked, estimated at 2.9lb at 3 months says she'll be around 6-7lbs full grown. Granted at 3 months, my baby was more around 3-4lbs lol, she's a chunk monkey ^^;. But yea, she'll grow like a weed and that amount doesn't sound too much, they'll expand and shrink alot lol when I got my girl she'll be "fat" one week and "skinny" the next. Vet told me it's normal they'll fluctuate because they eat lots and burn it off with play.
At this young stage they can be prone to hypoglycemia so it's good to have either nutrical (preferably) or karo syrup incase she gets the shakes, those help get the blood sugar up quick but she'll still need something afterwards to keep it stable. I use wellness as well, my girl always has a beautiful coat from it ^^.
__________________

R.I.P. Mick & Mandy (before 2010), Mila - 4/3/15, Chloe - 2/18/16, Kimchi - 6/2/2021