Does the size of ball pythons matter when they are housed together?

Question
I have a soon to be breeding pair of Ball pythons.  Sybil (female) is 10 ounces and Sababa (male) is 10.8 ounces.  I know they are too young to breed, but we are hoping later that they will.  Sybil was given to us and they said she was captive bred and Sababa we got at a reptile expo. He is captive bred.  We are heading to a show tomorrow and were curious if we could get a smaller ball and place them in the same terrarium.  I know not to put them together immediately. I have a smaller 20 gallon to put the possible new edition.  Sybil and Sababa are in a 100 gallon aquarium.  The temp stays around 85-87 during the day and 72-75 at night.  They do have a water fall so humidity is around 60%.  I use 100% organic cypress mulch as substrate. Heating is provided by heat lamps and I have a UVA/UVB bulb above the waterfall.  If I can place a smaller ball python with them, should we get a male or a female.  I would like to have another Female.   Thanks for answering my question in advance.

Answer
Hey Whitney,

You can house them together and yes you right you should quarantine them first for at least a month.

If you plan on breeding them you are best to house them separately. This way they do not get used to each other and do not breed.

Good luck and let me know if you need anything else.
Eric