Hitchhiking with children
Hitchhiking with children seems a big challenge. But in reality it is a big advantage, espacially if you look like mum/dad hitching with their child. Drivers are maybe also willing to drive detours for you and your child because they really want to help.
In many Western countries children have to be in special children car seats until a certain age (e.g. 7 in Australia). It's certainly a drag to carry these seats around while hitchhiking. If it is law to have such a seat, it is a good practice to show to the potential drivers, that you have such a seat in yor hitchhiking inventory.
About your hitchhiking partner
When hitchhiking with your child, your child will become your hitchhiking partner with all the needs a child will have. "I am hungry, I am thursty, I need a toilet, It is boring, ...". Especially when on the road, the needs of the child shall be your priority one. That means also, that you will probably not as fast as you may imagine, even if the willing to stop from the drivers is much higher. So, you should not focus that. Even this should be clear, it should be just mentioned, don't hitch with a child only to get the "hitching with a child bonus". Most parents, and for a good reason, teach their kids to not enter cars with people they don't know. It is important to explain to your child why in this special case it is okay to do it. In any case, your child should feel comfortable to hitchhike with you. If not: Just don't do it.
For teenage hitchhiking kids it might be a good idea to make their first hitchhiking experiences with a mature, hitchhiking experienced partner.
The road and especially the highway can be very dangerous. Make sure your child stays safe at all times. Good idea might me to let your child take a seat on your backpack and you are the one with the thumb up. Never leave your child alone or unobserved. Further, don't let your child enter a car first. Always together or you first.
Apparently, in Poland there were TV advertisements saying it was perfectly safe for children to hitchhike on their own until sometime in the 1970s.
A Polish driver told Fverhart that his father used to hitch-hike with him when he was a child (era of Polish People's Republic). His father would put him clearly visible and drivers, certainly female drivers, would almost guaranteedly stop.
In 2021 Quarim hitchhiked with his three years old daughter (because of a special situation he was in) and almost everyone stopped.