Is your 0-24 dive number correct? That's generally less than you'd want for Egypt - it has some great diving, but it's a lot riskier than e.g. Southeast Asia, with currents, bottomless walls, shadier ops, general culture of risk acceptance.
By all means go, but take any extra chance to prepare that comes your way.
Going as a family, dive diversity won't be the limiting factor. Dahab is easily worth three weeks of diving, Sharm el Sheikh about two months. That's what it will take you to see the sites. Your stay-in-one-town duration will likely be more limited by your family's tolerance for Egypt, which isn't all that welcoming outside of the big tourist traps.
By all means go, but take any extra chance to prepare that comes your way.
Going as a family, dive diversity won't be the limiting factor. Dahab is easily worth three weeks of diving, Sharm el Sheikh about two months. That's what it will take you to see the sites. Your stay-in-one-town duration will likely be more limited by your family's tolerance for Egypt, which isn't all that welcoming outside of the big tourist traps.