DALLAS (CBSDFW.COM) – Mary Lewis has refused to leave Children’s Medical Center of Dallas since New Year’s Day.

She’s there all day every day by her daughter Brianna’s bedside. “I haven’t stepped foot outside. It’s been 22 days and I haven’t left and I’m not going to.”

Brianna is almost four months old, and has Acute Myeloid Leukemia (AML) a cancer of the blood.

Mary says over the holidays Brianna was running a fever and so she got worried.

Brianna’s parents rushed her to the hospital in Tyler and after a number of tests found out she had Leukemia. She was immediately brought to Children’s.

“It’s pretty crappy to find out on the first day of the New Year that it’s going to be the worst year of your life,” says Mary.

So far Brianna has had four surgeries and seven blood transfusions. “You don’t want to see her with tubes in her nose and all over her body,” explains Ben, Brianna’s father.

While at the hospital the Lewis’ have started a movement of sorts on Facebook. They’ve told anyone who will listen to go donate blood, not just to give to their little girl but all the other kids who need blood on a regular basis.

“You look at her face and it’s white and really slow respirations, that’s not being alive. You give her blood and a few minutes later she is nice and pink and the happy baby I remember before all of this happened,” says Ben.

Carter Blood Care supplies blood to about 95% of health care facilities across North Texas, and as always they are in need of more blood. From about Thanksgiving to February their donor numbers are down.

Type O negative and B negative are the types the blood center is in desperate need of. “People just don’t know what kind of gift it is until you have to have it,” says Mary, “If it wasn’t for that person out there she may not be alive.”

The Lewis’ will be at the Children’s until the summer. They are optimistic Brianna will go home and thankful for so many blood donations already.

“We have to fight this thing and I don’t see any other option other than her beating this thing and living normal childhood for the rest of her life,” says Ben.

If you would like to donate blood, check with the Red Cross, or Carter Blood Care.