Those medical transportation services are great -- IF someone knows exactly when they need to be wherever it is that they are going and everything can be nicely schedule. Yeah, that doesn't work out so well for situations such as being picked up after a surgical procedure at a hospital, as even once someone has their discharge time scheduled, it still could take another hour or two (or worse, longer!) for the medical transportation vehicle to arrive to pick them up. Those sorts of systems work really well when one has a specific schedule both coming-and-going and can plan ahead accordingly, but otherwise, big FAIL.
For a while I was on the board of an organization which serves the visually impaired and others in the DC area, and when we had our quarterly board meetings, the visually impaired members were often so frustrated because either they arrived way too early for the meeting because of the MetroAccess schedule and prearrangements with the service, or were late for the same reason, and more than once another (sighted) board member and I waited with one of our visually impaired members for a while after the meeting had already finished up because the MetroAccess vehicle had not yet arrived to pick them up even though they'd sent a message with the estimated time of the end of the meeting. These members of our board were trying to maintain their independence, but wow, at times it was just so frustrating for them to get from Place A to Place B and back again! Some of them had family members who provided transportation, but other did not or the family members were unable to help out at that particular time. A few times other (sighted) board members with transportation who happened to live in somewhat of the same general vicinity were able to give someone a ride home, too, but that didn't always happen since we were from four different local jurisdictions around the area.
That's good that your son-in-law will be helping out with this outpatient surgical situation, then. Can he take Mrs Foofer Doggie to the hospital, too, drop her off after ensuring that she has someone who will escort her to where she needs to go, and then later when she is informed that she will be discharged, she can call him and call you and he'll be able to get back over there (with you along for the ride, too, of course!) to pick her up and drive her to your home? That seems like the best, safest, most comfortable solution all the way around -- keeping things in the family, keeping things out of the realm of public transportation such as Lyft, etc., etc. (and I can understand the medical staff's leeriness of Lyft), using a safe, comfortable and private means of transportation, your son-in-law's car, rather than you taking her home on your bike!