Of course you can have a GSD without it being aggressive. First step is to find a good breeder- one who titles or works their dogs and carefully selects the parents to produce sound offspring (the parents should also have their hips/elbows certified). You need to figure out what lines of GSD you want, showline, working line. So research the lines and which would best suit your lifestyle, then research breeders that breed those lines.
Second step is when you get your puppy to socialize him/her. Take them everywhere, let them meet lots of people, take them to puppy training classes.
You can train the dog to go to a special place when people come over (like their crate or bed) and then release them to say hello. Or if strange people are coming in and taking your grandma on a stretcher, you may want to just crate him/her for that time.
Edit: I agree with Mrs. K- finding an older dog sounds like it would be a better fit if it's your grandma raising the dog. I foster GSDs and many dogs in rescue are already housebroken and have good manners and are well socialized.
If you and the rest of your family have the time to properly raise, exercise, and train a GSD, then maybe a puppy from a good breeder. But keep in mind, a GSD is going to be a lot more work than a shih-poo.
ADCH Mikko (USDAA) SCH-B; (NADAC) EAC, EJC, TN-E, TG-E, VerO; (AKC) NAJ, CGC; (NACSW) NW1 - 9 year old GSD
Last edited by I_LOVE_MY_MIKKO; 01-08-2012 at 10:38 AM.