The following characters are members of the Solters family who work for Crosstime Traffic in Gunpowder Empire:

Amanda Solters, daughter of John and Melissa, sister of Jeremy, POV
Jeremy Solters, son of John and Melissa, brother of Amanda, POV
John Solters, husband of Melissa, father of Jeremy and Amanda
Melissa Solters, wife of John, mother of Jeremy and Amanda.

Peripheral members:

Beth (surname unknown), apparently a sister of Melissa Solters, mentioned in passing.
Fafhrd, the Solters family cat.