A bird cage is NOT appropriate housing for guinea pigs! It is far too small and the wire bottom will hurt their feet. The spacing of these bars is so far apart, they may even have their feet slip through and break their legs. Put some cardboard down as a temporary measure until you can get a new cage.
Also, you said one is a male and one is a female. Please separate them. Breeding is hard on females and many don't survive giving birth. You also don't know what kind of genetics you are passing on, not to mention you will be adding to the overpopulation problem.
