my puppys aggression...

Question
How am I to keep a pup whose very unpredictable in it's behavior moods I call them. I have a 3 1/2 mth old English springer and she's wonderful with all areas except her aggression around the food dish and ownership of her chew bones.. etc. Her breeder has advised me to give her a good shake down, showing I'm the alpha dog, but I'm in my mid fifties and have no arm strength to do such a routine each time I feed her or I wouldn't anyway for it's showing me to show meanness and aggression which I find seems to get her worse. She's attacked my husband, bitten my daughter at the back of her heals and now we have a granddaughter coming to visit in August of which I'm considering taking the dog back to the breeder.. help!!

Answer
First, you bought from a less than knowledgeable breeder in the first place if she tells you to "shake a dog down".  This behavior is a danger signal in a young puppy, but it isn't reason to physically aggress against the pup.  
First step, get rid of all chew bones for now.  Do not free feed the dog.  Every member of the family should go through the protocol in this book NOW:
"Mine! A Guide to Resource Guarding in Dogs" by Jean Donaldson.  You can get the book at dogwise.com
Immediately, if not sooner, get this dog in a play group or day care with other puppies (so she learns that she isn't the biggest kid in the playground) AND sign her up for puppy class with a good positive trainer.  Find one at one of these sites:
www.clickerteachers.net
www.trulydogfriendly.com
Taks absolutely no training advice from your breeder, who is still living in the dark ages of dog training!!! You will live to regret it.  Aggression begets aggression!  But, you must get this under control now, so do get the book, and if you like reading, do yourself a favor and get Jean's other book, too: "The Culture Clash".
Do not pull things from this puppy's mouth and don't yell at or chase her if she grabs something that isn't hers (makes guarding worse).  Instead, whack yourself with a rolled up newspaper for letting it be on the floor or anywhere that puppy could reach it;-)))
If she does get something you don't want her to have, trade for it.  Get a cookie (most puppies already know where the cookies come from).  Offer the cookie, or even a piece of real meat, as you say "trade?"  When she drops the item to get the cookie, give it to her as you pick up the object, and say "good trade".  She will eventually learn that trading is good, and you will have accomplished "object exchange: without making her feel guard-y, or putting yourself at risk of a bite.  Later, when you re-introduce chew bones, you will hold one end of the bone (so she thinks it belongs to YOU) and trade back and forth for it - she will only be able to chew it at first while you are holding the other end of it. Leaders aren't unpleasant - but they DO control resources!!!
I hope this information helps, but one caveat.  There should be no food about when grandchildren are in the company of this dog.  You may be able to prevent her from guarding altogether by using the Donaldson protocol, since the pup is so young, but just to be on the safe side, you need to know that occasionally, a guarder will do it with kids, when they know they can't do it with adults.