i wouldnt recommend a venomous animal to be around a child, especially not a 4 year old. keep it locked in a container and the kid can look at it and watch it hunt and web. the venom is extrememly dangerous to small children and all it takes is that 1 in 50,000 times you hold the tarantula for it to go severley wrong. a bit to a 4 year old has a high likely chance of limb amputation and life long nerve damage.
EDIT: oh i forgot to add T's make great pets for young kids as they dont require daily maintenance and kids have a habbit of going off of things. not to mention your kid wont be one of those annoying people with a fear of spiders and kill them on site
EDIT: oh i forgot to add T's make great pets for young kids as they dont require daily maintenance and kids have a habbit of going off of things. not to mention your kid wont be one of those annoying people with a fear of spiders and kill them on site