Hi,Your pictures need to show the vent (underside waste exit) from the side. A outward bulge signifies a male, a female doesn't bulge. This is not a 100% correct process and is easier to do as they age. Congratulations on being Cham grandparents, you must be proud!
Hi,Are these baby veileds? If so you don't need the vent just the back feet like you have. This one looks like a female but a side view of the back feet would probably be easier to determine if it is.
How old are they? They look very young, so the males won't start showing banding or colors till about 4 months.