you missed something. agreed it's llC. and the IRS states using your link that they can't file as a qualified joint venture using to schedule C's
A qualified joint venture, for purposes of this provision, includes only businesses that are owned and operated by spouses as co-owners, and not in the name of a state law entity (including a limited partnership or limited liability company). thus being an LLC they can't use 2 schedule C's.
the issue is how much work the spouse performs. In any event if she is paid more than $600 as an independent contractor he will have to file an 1099 for her.
however, I would suggest that the taxpayer use this link to go through the factors the IRS would use to determine IC vs employee status.
https://www.irs.gov/businesses/small-businesses-self-employed/independent-contractor-self-employed-o...
