Putting up educational pictures for children

There is
nothing wrong with teaching children the alphabet by writing letters with
appropriate pictures, even if they are pictures of animate beings, because
of the concession allowing “dolls for girls”, and because concessions may be
granted to small children that are not granted to adults. Putting up these
pictures will not do any harm, because they are images that are permitted,
unless the pictures are put up with the aim of venerating the images
themselves; if there is no such intention and the pictures are permitted,
there is nothing wrong with having them on the ground or hung on the wall. 

See also
questions no. 137174 and
20325 

And Allah knows best.