Pretty sure I got the surname from the Reikland gazetteer, so yes.
Great! I've actually been compiling a small simple list of Imperial families to keep an eye on, and I came across the Jungfreuds as a result. In case you're curious:
Averland: Leitdorfs (current Elector Count family), Alptraum (former Elector Count family, rivalry with Leitdorfs, probably trying to regain power).
Wissenland: Von Liebwitz (current Elector Counts, also the Counts of Meissen and Nuln, have control over Wissenland), Toppenheimer (Control over Pfeildorf and significant chunks of former Solland, strong family. Also control Hornau in Southern Stirland), Pfeifraucher (control over Kreutzhofen, which is a crossroad between the Empire, Tilea, Border Princes and Bretonnia all at the same tme).
Stirland: Van Hal (current Elector Count family), Krebs (Barons of Marburg, Headmaster of University of Nuln is a Krebs), Halstedt (Counts of Halstedt, control over the Moot Road, Magistrate of Nuln is a Halstedt).
Reikland: Holswig-Schliestein or whatever (Emperors, Counts of Reikland, Princes of Altdorf), Gruber (own and manage Weissbruck, known for its wine, produces a lot of money), Jungfreud (Counts of Ubersreik, not yet a Free Town but it's very powerful), Wallenstein (somehow they're both the Barons of Wurzen in Ostland and the Grafs of the Free Town of Auerswald, which is a county in its own right), Saponatheim (Grafs of the Free Town of Bogenhafen, strong trade presence).
Ostland: Konigswald (current Elector Count, control over Wulfenburg), Von Raukov (Counts of Ferlangen, become Elector Counts in canon), Von Wolder (Barons of Salkalten), Wallenstein.
Nordland: Nikse (current Elector Counts, control over Salzenmund), Gausser (Theoderic takes over in canon, nothing about his family is ever elaborated), Kohler (Counts of Dietershafen, the Baron's son is the Sea Lord of the Second Imperial Navy in canon), Neurath (Barons of Norden, secretly plotting to build Norden into a base to conquer Lustria).
Middenland: Todbringer (Elector Counts of Middenland, Counts of Middenheim and Delberz, great power and control), Bildhofen (Magnus the Pious' relatives, biggest competitors to the Todbringers, Counts of Carroburg, Leopold Von Bildhofen thinks Middenheim is a leech on Middenland).
Ostermark: Hertwig (Elector Counts of Ostermark), Husserl (Landlocked Barons), Mach (Margraves of Eisental), Shurz (Margraves of Essen), Rontgen (Margraves of Fortenhaf).
Hochland: Ludenhof (Elector Counts of Hochland, almost completely dominates Hochland's power structure. It's a small place).
Talabecland: Feurbach (Elector Counts of Talabecland, Counts of Kusel, technically control Talabheim), Krieglitz-Untern (Great power and influence over Talabheim, took control when Feurbach disappears in canon), Donn and Bruckner (Barons of Lieske and Ossino respectively, EIC should maintain good relations with them).
It's not comprehensive, but I just kept track of the families that I think would be relevant in the politics of DL. I kept track of Eisental and Essen because of the Ostermark Canal being in their territory, Fortenhaf because Shirokij forest, where Ostermark is deploying its army, is close to it. I also kept track of Husserl because we met them, Kreutzhofen because it was used in the bombing plot, and I think Bildhofen, Gausser and Kohler might become relevant.