Hi Waves,
I nursed my little girl through H1N1, so I know it's frightening.
If your Mom's situation is stable, chances are she'll make a good recovery. However, if she's having any difficulty breathing, seek help ASAP. With your Dad's underlying condition, you might want to consider Tamiflu as a preventative.
The others have given you good advice on avoiding the flu yourself. I would add that your Mom should wear a mask, especially if she's coughing.
Keep us posted.
Thinking of You