You have no problems for 2023, given that she lived in the US more than half the year, and did not pay more than half her own support (when considered over the entire year).
For 2024 and 2025, the question of whether she is temporally away but considered to live at home, depends on her demonstrated intent to return home or remain in Germany, which is not known yet (you said "may or may not".). And even if intent to stay in Germany is still undetermined by the end of 2024, her income might defeat the dependency test for 2024. But you can figure that out when the time comes.
Your daughter should also be reminded that as a US citizen, she must file a US tax return and pay US tax on all her world-wide income, even if she is living and working overseas. She can claim a credit on her US tax return for taxes she pays to Germany on the same income. Her US tax return is filed according to US tax law, regardless of how her income is taxed Germany.
