I have a similar situation.  We live in TN.  I work and receive a W2 from my employer here in TN.  My wife works for a company in IL and receives a W2.  We are filing an IL state form for that piece.  But on the side, my wife is a contractor for a company in CA.  She has done a small amount of work for them and received a 1099-MISC.  We are unsure if we need to do anything for CA, like a nonresident form.  Since we are filing jointly, does that matter? (https://www.ftb.ca.gov/file/personal/residency-status/part-year-and-nonresident.html)

@msurwl.

MinhT1's answer above applies to you as well. I'll repost it here.

No, as the work is done in Texas, your 1099-MISC is considered as income earned in Texas, even if the company is based in California. You do not have to file a California state return.

I'm being told that according to a case ruling in CA any income on a 1099 MISC in California is subject to taxes in California. 

https://whyblu.com/blog/nonresident-sole-proprietors-1099-income-from-california-customers-is-taxed-...

You need to file a California State return from a 1099 MISC if it is for work that was performed in California.  The only exception would be if you performed work in another state and the 1099 MISC was issued from a California address. This link, explains this phenomenon. As far as that link you provided, this would not be considered a reliable link for tax information.