I need help making an end of life decision regarding my elderly dog. SHE IS NOT SICK, just getting older

My vet is a good vet but she is very unemotional and even though I have asked her several times if it is soon going to be time she evades the question or outright ignores it. Now I fully understand that this is MY decision about my own pet but I am in need of some guidance and I am certainly not getting it from her.

Some background: female dog, age 13 cockapoo. I brought her to the vet a year ago for lumps in her mammary glands but they are not cancerous at this point. Surgery was discussed for that as well as tooth extractions and we decided that given her advanced age, the trauma and the cost of doing the surgery it would be cruel to put her through all of that. We had actually mentioned euthanasia at that point but it never really happened.

Fast forward a year. She has started peeing on my bedroom carpet after 13 years of never doing so. At first she was doing it at night so I thought perhaps she was trying to wake me but couldn't. I took her to the vet 2 days ago with a urine sample. That came back clean so we opted to do some senior animal blood work ( I am sorry I don't recall the correct terminology). That all came back clear. No kidney failure, no weird blood cell counts, nothing. Everything is fine. I left her at home for a few hours today which isn't at all unusual and she had peed AND pooped on my carpet.

After 13 years of sleeping in my bed kenneling would be cruel and a nightmare for the whole household. I can keep her away from my room and all furniture when I am away from home via a baby gate but that doesn't resolve the night time urination. I have tried puppy pads but she just pees beside them. My parents dogs were hear in January for 2 weeks like they are every year and they always go on my damn carpet (I get the carpet cleaned every year after they leave) but this has never affected maggie at all. (And no, removing the carpet isn't an option as I rent. The carpet cleaner gets rid of all the smell though)

I don't know what to do. I know that preventative measures are necessary and I am willing to take them but how do I know when she is simply getting older, maybe struggling with senility and incontinence or something else of that nature? She is also making a different whining sound sometimes when she is lying with me... one that I have never heard before so I am worried that she is in pain. She is slower going up and down the stairs but still playful. If she is walking, especially off leash she easily keeps up with my 4 yo dog. She is going hard of hearing.

I don't know what to do and I need some sort of guidance so that I can be better equipped to make this life changing decision for us.

Edited for clarification