She is a sweet kitty and lost her human mommy 3 yrs ago. her sister seems to be thin from heat too and has the third eyelid showing a lot but this could be because they sleep all of the time. I've wondered about maybe worms but I haven't seen physical signs in their bowel movements

I would say it is a sick cat -- maybe has worms or a blockage. In my experience it is not in a cat's nature to poop where it likes to hang out, and incontinence is a clear sign.

She is so weak that you have to carry her? or she just doesn't want to go out?

I've never noticed that heat caused my cats to lose weight, it causes them to shed!

Having the 3rd lid visible at all times is also not normal, if it is so when the cat is awake.

They will urinate when upset or annoyed or whatever. My very elderly cat started to do so on my bed where she had slept for a decade, after we had another cat and a dog move in, possibly because she had difficulty negotiating the stairs and other animals in the dark, or because she was just upset at the changes in her environment.

Tripod needs to be seen by a vet.....and tell Frank to take the other cat when he goes. Lethargy, losing weight and having to be carried are not good signs. Since her name is Tripod, does she have only 3 legs? If so, it's possible she's dealing with arthritis along with an illness.

Also, since there are new cats in the house, how many litterboxes do you have? There should be at least 3 and Tripod needs one of her own in the bedroom.

Maybe your cat is just jealous of the new females and wants to get your attention. I have also read online that experts believe that cats developed marking behaviors to minimize contact with other cats. Marking their territory is their primary means of communicating with other cats and letting them know another cat is in the area.