If you can't get a new tank right now their are also containers you can by at LFS that are designed to hang on the back of the tank you can put the mother in their and when she has the fry they drop down in to another part so she can not eat them. Then when she is done you can take her out and leave them in their for a bit till they get a little bigger. Plants are also really helpfull you can get wisteria or another plant to float on the top for them to hide in.