Its less stress on females for a time with multiple females,..however many "selected or alpha" females will dispose of extra competition,..watch for that. There is a lot of confusion about jewels because they behave very differently to each other and to any others who may be with them. I have a pair of turquiose jewels that never bicker with each other, raise young to overcrowd, but try to kill anything else in tank. I don't like any sacrificing, so they have a 20 long to themselves..pretty soon they will need a 55, as they are hppy and growing. I've had red jewels that my males would kill the female as soon as fry hatched..the entire strain seemed inclined to behave this way. My opinion is you must judge behaviours on individual basis and envirenment.