Okay:
DO they have, experience at babysitting... already???
AND for an INFANT?
And for kids, that are the ages of your older kids?
Personally, I would not want Teens, to babysit my infant.
Unless, they have GOOD solid experience, and references.
Do they know how to cook or prep food? Or feed your kids whatever food you have? And know how to put the kids to bed? And/or know how to feed an infant... and that that means, feeding the infant on-demand? Do they know an infant's, cues for hunger, etc.?
Night time care... is sometimes more expensive.
How 'late'... are they expected to stay there?
What is their, bedtime?
IF they are CPR trained AND First-Aid trained... they would be certified. AND have the certificate card, too. To show you.
Which proves, they are then, CPR and First-Aid, certified.