I really don't know what to say that other reviewers haven't. Mary is extremely nice, social, and accommodating. I stayed for a month...and dare I say, I started to feel a bit at home.
The room she lets out is spacious, with its own bathroom and door to the backyard (where she let me keep my surfboard), deck, and garage (where she let me keep my bicycle alongside her beach cruisers). It gets plenty of light and a decent breeze through the windows (even more if you open the door to the deck).
Her dog is playfully weird and talkative... and only slightly rambunctious at times. He's funny and is also a good host.
Mary's place is in a great location... Really ideal. (Note: airplane noise is the only downside to OB... Any place in OB will have noisy planes. Do NOT let this deter you from visiting this great neighborhood). A 10 minute walk to OB Noodle House, Mike Hess brewing, and a local supermarket. A short bike ride to the beach or "downtown OB" where there are some great places to eat. Sunset Cliffs park is only 3 miles away and the coast makes a great bike ride ... or if you run like me, a great long run.
Uber rides anywhere you want to go in SD are no more than $10... So I found I never had to use my car... Which to me is a huge quality of life bonus!
Seriously, you can't go wrong here if you want to stay in OB.