.... Does My Mother Really Have Leukemia?

So, I remember coming home and my mother tell me and my brother she has leukemia.
My mother is a NOTORIOUS lier. She even told me I had thyroid cancer.. went to the doctor and they basically looked at me completely stupid and my mother and said no. It came back negative.
She jumps to conclusions and "expands" anything she says.
EVEN when I easily prove to her that yea, she lied. But she doesn't care. She still does it lol.
But she hasn't been to ANY doctors... no Chemo... nothing...
and it's been 4-6 years since she told us.
I even caught her in a lie when we were applying for something and it said to list your disabilities and she didn't even list Cancer.
I asked her, you sure you aren't forgetting anything?
She said no and I had to remind her about her leukemia and she said OH! yea add it.
I don't trust my mother, She's just a bum in my opinion.
I pay my bills, Own my car, buy stuff for the house since she's a pot head.
Give her money when she needs it and let her use my car when she wants.
I can't say no to my mother but I work on the computer and I make 3x's more than her.
But does it really seem like she has leukemia?
She's gaining weight if anything... few months ago she was a size 5 and now she's a size 11/12... so yea. Not sick imo.
Just someone living THAT long with leukemia doesn't seem... real.
I mean NO TREATMENT or anything. Did she just lie to try and get her ex husband back since he caught her cheating.. NUMEROUS times?