Turbo Tax only asks if Lisa (me) is incapable for the Family Tax Credit but how do I list Scott (spouse) who is physically & mentally afflicted with Parkinsons Disease?

Which state are you referring to or which credit?

If you are working and need to pay someone to take care of your spouse, then you can possibly claim the dependent care credit. 

If you are filing a joint return with him, then you can select his name from the drop down.  You cannot claim this credit if you are filing separately.  He does not need to earn income in order for you to file jointly.