Do you have any experience working w/infants?
If the baby is being exclusively being breastfed, & hasn’t had a bottle yet......then I find it harsh that the Mother would leave her baby w/you and a bottle.
Like another poster stated - - harsh for both you AND the baby.
Hopefully that is not the case however.
My best advice would be to make sure the milk is warm.
Other than that, good luck.
Hopefully the baby has had some bottle feeding experience.
If not, hopefully Mom will be very supportive of any challenges that you may endure.
Hope this helps!