More so than ever before. Google search has become incredibly local in nature for many searches.

While you don't have to use the post functions, there's some evidence that those that do so see a little lift. It's also a good way to stand out. You take up more real estate in the search results when your post shows up along with your business listing.

Reviews are also very important these days. Put plenty of effort into getting reviews on both Google and Facebook (Google also factors Facebook reviews into rankings) and Yelp to a lesser degree. Make sure to respond to all reviews too. A simple thanks to the person can help build that relationship and make them more likely to recommend you. If it's a negative review, address it. People like to see that a business is willing to try to fix things when they're not right or at least address it in some way.

I'd recommend going through each section in GMB (each of the tabs on the left) and making sure everything is filled out as completely as possible. The more you can give Google about your business, the better. Then ever month or so I'd go back in and make sure your info like address and other contact stuff is right as people often submit corrections that are wrong.

Either your client lists her home address (if you do this you can try adding Suite 1, or change any apartment # to suite) or she can rent a virtual address (about $8 a month).

Reconsider the "Service area business" option. service area business is what your client is. She doesn't want her physical address listed correct?

Edit: everyone says google flags virtual offices... so dont do dat