The bathrooms at Frankfurt's terminal 1 were excellent. There is a private bathroom located near each of the regular public restrooms. The private bathrooms are large, have grab bars near the toilet, and the toilet even disinfects the seat after you flush!

The LH staff were outstanding and provided an attendant at Frankfurt to guide me from my arrival gate to the connecting gate. FRA also has a lounge specifically for unaccompanied minors and pax with disabilities, though I did not visit it.

In general, FRA terminal 1 was wheelchair-friendly and spacious--much more so than IAD, which is horribly overused and congested with pax, ad hoc renovations for security purposes (which greatly constrict maneuverability), and the somewhat wheelchair-unfriendly 1960's era "moving lounges" (hopefully to be phased out soon) for transport between terminals.