how many fish in a gold fish bowl

Question
My daughter's friends gave her a 1 gallon bowl of goldfish for her birthday.  It has no filter but we did add a bubbler.  There is gravel and a plastic plant.  We have been changing the water weekly and throughly cleaning the gravel at the same time, (with just water).  The friends gave three small fish initially and two died within the first month.  The third has been thriving and is now about two inches long.  Recently she wanted to add another fish and we got one from the pet store (I don't remember the name of the fish but the store clerk did know about our set up and said they fish were ok together).  However, the first fish appears to be bullying the new fish so we have set up a gallon jar for the new fish to keep it from being picked on.  
Here are my questions. I have never done fish tanks and so I apologize if my questions are silly.
Is there any chance the two fish can get along?  
Is there enough space for two fish??  
If we got a bigger tank, would that make fish #1 less agressive to the new fish?    
How do you know how many fish can be in a tank or bowl?
Does a goldfish need "friends"?

Answer
Hi Jacque:  First of all... there are no silly questions because each of us... novice and expert... and sometimes I am both.. we all started in the same place...   I personal do not thing that goldfish belong in a bowl.  The rule of thumb for goldfish is one fish per ten gallons of water.  They are messy fish and they create a lot of fish waste. So with your original three... the water would go toxic in a day or two even if it looked clean.  With tropical fish it is usually one inch of fish per gallon of water (roughly) but gold fish are cold water fish not tropical and they can grow to be a foot or longer.  A larger environment may help the two fish get along or it may not.  Some fish are just bullies and fish aggression is something I get asked about a lot.   Goldfish do not need to be in groups... they are not shoaling fish and they seem to be just fine on their own.  This sounds like a case where less is  more.  Not all goldfish get along with each other so it is difficult for me to say is there is hope for the two you have.  It sounds like to me you have a fish that likes to be on its own.  You can also try to feed them more and see if that cuts down on the aggression.  Extra food works sometimes with more aggressive fish so it may work with your goldfish.  Keep me posted... and let me know if you have any additional questions.  dave