Perfect ideas ladies. Yes, I will give her the bill for the new latch and tell her I can not take the risk with her son's new found knowledge on how to open the gate.
We are also at odds regarding when her son will be able to wear underwear here. He still pees in his pull ups and does not tell me when he needs to go. Earlier this week, she speaks to her son (again on her knees in front of him - oh hail the mighty one LOL)" maybe this week Mimi will be nice enough to let you wear your underwear" so I just kindly said "sure, as soon as he stops using his pull ups and tells me that he has to go" and I smile. Her voice is always squeaky nice, but she always manages to deliver some little zinger.
Also Skysue, he is a sneaky little guy, so even if I told him the gate would be off limits, that would just egg him on to get to it.