I think 子作り is literally "have children", but I'm not sure if the じゃ makes the phrase imperative. If someone fixes or confirms add then the translated tag.

This image is a duplicate and the parent image has been translated. The translation in the parent, "Lets make babies", is preferable to the one here, "Lets have children", since the prior is more of a command and keeps the sense of impending action.

It is not an exact duplicate, this one here is a little bit lighter than the parent, which got slightly darker lines.

You're right, and the version here is the one currently on the artist's page. Seems the artist went back, edited the work, and saved over the previous version found at post #193149.