No, do not get a dog. My daughter really really wanted a dog, however, I really really really wanted a dog which is the ONLY reason we got a dog. You, the parent, the adult have to really want it. I am responsible for her behaviour (or lack thereof sometimes), feeding, exercise, general well-being. My daughter loves her dearly but never walks her . I did not expect her to walk the dog because I got the dog...therefore my responsibility.
You cannot leave a dog that long for the two days you are out.
Dogs are not a cheap option in terms of purchase (even a rescue will set you back about £150), upkeep - vets, feeding, insurance.
They are exceedingly time consuming.
My serious advice would be to get a pair of (same-sex!) guinea pigs. We got 2 when my DC were 3 and 5. They were phenomenal first pets - not scrabbly, not scratchy, hardy, fun little creatures who we all adored. One of them only just died aged just over 6.