Well I am certainly not "the dog whisperer"
and surely don't mean to imply that i have knowledge - just years of experience and this is what i have found - I am sure other breeders know what i am thinking here.
You never really know when they will come in heat the first time and its been my experience that you can't be positive of that second time either - If you keep them intact you can start to figure out a cycle - usually approximately every 6 months - Now that being said - I would suspect your girl is on a short cycle right now and she is marking ( yes girls mark too !! ) and doing all this strange stuff as the hormones keep changing in her body. Now i am not saying that spaying it the answer to house breaking
But i have found that when they are not spayed - its a lot harder to do.
I am sure you will get lots more ideas and help here on YT but i would move up that spay date if it were me and get that done and eliminate that possibility.
Good luck as i know how maddening it can be to get one totally potty trained -
Hope some one else comes up with other possible answers too.