Womanish and Womanly are the words which mean the same i.e to have feminine qualities or traits. However, the two are used in different tones.

Womanly is used in a positive tone to suggest approval for the traits seen in a person; the traits like calmness, modesty and motherliness which are admired by the society .
Shweta is greatly admired for her womanly grace.
There should be a womanly consideration for the convict in this case.

Womanish is more used in a negative tone to suggest traits in a woman which are not approved by society and traits in men which are not considered appropriate for them.
It is so womanish for a man to cry over trifles.
He sounds a little funny with that womanish shrillness in his voice.