The Economist had that item in which it refers to Dan Quayle in this way:

On the other hand, it is used almost in a derogatory sense when it means "a girl with an appearance of a boy" (that is, with a ring of "boylike" appearance).

Womanish seems like being more derogatory than its counterpart, so it is less used.

But it can be used in "childish" 

https://www.merriam-webster.com/dictionary/childish

Granted, most of the time is used with negative adjectives or with a negative sense (with the ring "undesirable quality" to it), as in "foolish/bookish/slavish/

But sometimes in neutral terms as in "feverish" (also meaning with "a little bit" of fever.)

Also neutral with numbers and collors: as in yellowish/thirtyish (approximately thirty - slangy way), etc.