Baby won't gain weight

she does we sometimes struggle to wake her up for the feeds we have alarms for

I wouldn't panic too much at this stage. My little one took 3 weeks to get back to birth weight. As long as the midwives are happy with your feeding then it can just take a little time, you're doing great x

They say to wake them, strip them off completely and change nappy. Or gently blow in their face. I strip my baby down and tickle her feet. That wakes her up for her feeds.

The main thing is that she’s actually getting milk - measure how much she’s drinking at each feed

Midwives said I should start formula feeding to top up my breast milk because at about the same age she wasn’t back up to birth weight however some babies just take a little longer to gain the weight

If you are really worried - try topping up the expressed feeds with formula but only after baby has finished that bottle and if you think she might still be hungry
There is a chance she is getting all the milk but breast milk might not be rich enough yet so she could still be hungry which is what happened with my sister x

(Side note but she is adorable

If she has wet nappies, poos and periods awake and alert I wouldn't worry too much.
It's good you are keeping an eye on her weight though. When my eldest was born he lost a lot of weight and slept a lot, the midwives completely stressed me out about it. When I saw the Dr they just said he was such a good weight at birth he could afford to loose more, and sleep a bit longer. He's now taller and stronger than me haha.
With my youngest two we didn't weigh them as often due to lock downs. Both lost weight initially but put it back on,l at varying rates.
Eldest was BF and topped up with formula. Younger two BF.

I wouldn't be stressing out bub isn't even a month old x take it easy on yourself hun ik it can be stressful and overwhelming, since your doing top ups with formula I would also suggest pumping after feed to try and help bring in your supply more as it will take up to 6 wks pp for your supply to regulate, also every baby is different and will gain their weight back eventually as long as they are back up to their birth weight by that 1 mth mark then it's all good x also keep hydrated and eat some more food throughout the day as it will provide some more nutrients through the milk

My baby was the same, only way we could get him to feed was stripping him to his nappy for a feed to wake him up x