Add a drain line for a kitchen sink to an existing drain line for a washing machine?

My sister is dividing her house to provide a living space for my aging mother. Since one bedroom borders the garage on one side and the kitchen on the adjoining side we would like to convert the bedroom into a small kitchen/living space. I would like to connect the proposed kitchen sink to the existing hot/cold water and the drain in the garage. Can this be done to code? I am a first time user, heck this is the first time I ever used a forum. Please help.

Lots of things are "possible". What determines whether you can do it or not usually depends on HOW you want to do it. One thing that may not be to code, at least in this area, is putting a kitchen in the bedroom. Here, a residence CANNOT have two kitchens, because then it has the potential of becoming a rental apartment which violates the zoning requirements in residential areas. We cannot even install a kitchen in a detached cabana for the same reason. If the customer wants one, we have to "hide" the plumbing for it until after the CofO is issued and the inspectors are all gone.