Don’t know if you have a specific area in West Seattle in mind, but I’d suggest the South Delridge/eastside of Westwood Village, or even White Center, near 15th & Roxbury, especially if transit might be viable for your GF in getting to the VA Hospital.
Metro Route 60 starts along the eastside of the mall, along 25th Av SW, then works its way up into the very southeast South Delridge area (Barton Pl, to Delridge), then onto Roxbury. It’s a bit of a “Milk Run”, probably taking a half-hour-ish from the starting point at Westwood to get to the stop nearest VA.
It should be noted that it is probably the equivalent of a few blocks walk between the VA and the bus stops (near McPherson’s Produce Stand, on the triangle lot, if you are familiar. So, if there are any concerns regarding her having to walk that stretch, that would need to be weighed in deciding if her riding the bus would be viable.
These areas would also allow you to use the Route 120, from White Center (originating in Burien), going down Roxbury before swinging over to the south side of Westwood, then up Barton Pl and north on Delridge on its way downtown. The last West Seattle stop at Delridge and Andover(?) would be where you and your bike get off, and continue over the low bridge to work.
Another option, if/when things get back to normal transit-wise, would be the 125, which, like the 60, starts out on 25th on the east side of Westwood, then up Barton Pl/Henderson, then north on 16th. It eventually rejoins Delridge after passing through South Seattle College, just s few stops before that last northbound bus stop on Delridge.
I think this area may also work well for the times your GF has to drive down to Tacoma.
Hope this helps, and good luck, and (hopefully) Welcome to West Seattle!