Can a group of women go out to a restaurant without mahram and have some Muslim lady fun?

Answer

You mean Iblees lady fun! Women who engage in such lewd activities suffer from the malady of prostitute-tendencies. They emerge from their homes under the Curse and Wrath of Allah Ta'ala. Mahrams who accompany them for their satanic tog are vile cuckolds (dayyooth) who also are accursed.