My DD2 was exactly the same at this age and it nearly killed me with the exhaustion - especially having to look after a toddler at the same time. It will get better - there are so many reasons for their waking and especially around this age there's a lot of brain development going on that means many babies wake a lot at this age. I found things improved when my DDs started walking or being more upright.

Are you able to rest in the day when she's having a day nap? Good luck with the sleep tonight x