What is her background? Has she seen the vet since this started? A housetrained dog that is having problems is doing it for a reason. This is going to be one of three things:
1) a medical issue. This is what you MUST eliminate as a possibility first. Make a vet appointment and have her properly checked for urinary or kidney infections (which will make a dog incontinent) or other possible issues. Some spayed females get spay incontinence and there are ways of treating this as well.
2) an anxiety issue. If you have only had her a month, she has gone through a total change of home, ownership, environment, probably food, lifestyle and the rest. You may be giving her more attention or less than she was used to. Often new owners give a bit too much attention to new dogs and that can cause a lot of nervousness and anxiety for the dog which the owner may not notice or know how to see (signals can be very subtle). This is very typically expressed in toilet problems -- it is reassuring to the dog to mark its new territory with a scent (eg its urine). I run irish Cavalier Rescue and I always tell new homes to treat any new adult dog as a puppy and have those expectations regarding housetraining. MOST rescue adults will have accidents. So approach taking her out as you would a puppy. Praise and reward with treats the moment she finishes going -- carry some treats with you when you go outside.
3) She wasn't fully housetrained to start with, or doesn't at this time recognise your house as a place where she should not go. Dogs don't get housetrained then automatically think "all houses are where I should not go". They tend to learn a territory where they should not go. If she never got out much, and mostly stayed inside at one house, or outside at one house, she probably has little idea that housetraining extends to other homes. Hence -- back to number 2 above -- you need to treat her as a puppy when it comes to housetraining and manage her as if you are starting from scratch (but an adult needing some remedial work will learn very quickly!)
I strongly recommend you immediately order Shirlee Kalstone's book on housetraining as it gives very structured approaches to housetraining and includes guidance for remedial housetraining for adults.
But have her vet checked first!! A simple urinary tract infection (UTI) can turn into a very serious kidney infection if left untreated and either way they are extremely uncomfortable to painful for a dog so she should be checked for this. Some females are prone to UTIs.