I should have italicized the word
may in my suggestion.
If you were just an average parent with no additional challenges coming to Guest Relations and ask to use a stroller as a wheelchair, they would certainly tell you no.
It will all be in how you can explain your needs - i.e. you have 2 very small children (possibly neither able to walk) that your DH will have to handle by himself. Besides that, you are going to be driving an ECV, which will pose additional challenges compared to a single parent who is trying to keep their children away from strangers using ECVs in line. Your children are going to want to get to you and it will not be safe for them to be underfoot (or underwheel

) of the ECV. Having a stroller in line would assure the safety of your children and make it easier for you to drive the ECV safely.
(You still have to worry about
other people's children, but at least they would be less likely to approach you than your own children.)
If you have a carrier of some kind that either fits child in, that would also be helpful to have. Your DH would be able to 'wear' one child, making his task easier.