Part of the problem is that the Bexar Co courthouse (and indeed central Texas) experienced a very bad flood in Sep 1921 from a hurricane remnant. Death toll was 215 from the flooding and damages were over 19 million dollars over 5 counties. Rainfall was higher in the northern counties- but San Antonio is downstream of the major rainfall- and the river runs right through downtown- just like it does in Austin. So, in SA- the river was 10' ABOVE flood stage... This was really a significant event, and sadly many early county records were destroyed. This may be a reason why you probably cannot find anything. In 1910- your family record indicates that the family was in the floodplain, south of the river- but within 2 blocks.... I am willing to bet that if they were still there, or she was still there in 1912 after her stepmother died, she wasn't there after 1913- which is why we don't expect to find them in the same place in 1920....
There was actually a worse flood in 1913- "water was waist high in the streets" Link to archive photos
You can see how deep the water is by looking at the horses in the street... This may have affected the neighborhood where your Aunt Artie lived. Look it up on Google Maps (Morrill Park, San Antonio.) Morrill Avenue dead ends near the river....
After two floods, the city built the now famous "riverwalk" and sorted out some dams and flood control- but for those looking for records- the damage was already done.
I think the cemetery you might be looking for is Alamo Masonic Cemetery, on E Commerce (abaout 5 miles away from Artie's old house). I know where that is, actually. I can't do it this summer- it's too hot to be outside during the day for longer than about 15 minutes at a stretch- and people don't like you to prowl around graveyards at night- although in Texas, that's about the only time one can be outside this time of year without liters of water and gatorade. The other thing to know is that there is also an Oddfellows cemetery a few blocks away on Hondo. These are your two best options for a Masonic Cemetery in Bexar county- right on either side of the San Antonio lodge. You might also consider contacting the lodge with your query, as they may have records that the courthouse does NOT.... They were far enough away from the river that they probably did not flood! :)
Here is a website that might bear fruit if you have not already checked it
This has a not-all-inclusive list of cemeteries, but lots of possibilities for you....Also, if you rule out the others, and you are pretty sure they are here, I can try to help you find some gravestones when the weather turns....
If I were you, I would try contacting the lodge first, and also send me a Private message (as we should take this off board since this is just the two of us commenting here). I'll give you an email addy and we can correspond there about these records, as there are 18 cemeteries in and around the area with the two Masonic cems, that may all be options, which is too long a discussion for boards. I can send you a map.... :)