I think plaintiff Mr. Elshikh's concerns about his mother-in-law obtaining a visa would be resolved by this provision of the Executive Order: 
"...the Commissioner, U.S. Customs and Border Protection (CBP), or the Commissioner’s delegee, may, in the consular officer’s or the CBP official’s discretion, decide on a case-by-case basis to authorize the issuance of a visa...
Case-by-case waivers could be appropriate in circumstances such as...
(iv) the foreign national seeks to enter the United States to visit or reside with a close family member (e.g., a spouse, child, or parent} who is a United States citizen, lawful permanent resident, or alien lawfully admitted on a valid nonimmigrant visa, and the denial of entry during the suspension period would cause undue hardship..."

The Executive Order may be reviewed at: https://www.whitehouse.gov/the-press-office/2017/03/06/executive-order-protecting-nation-foreign-terrorist-entry-united-states