has there been any pressure in Germany to remove these feminine forms of professions
On the contrary; talking just about Lehrer (using the "generic masculine form" that used to be common) will get many people angry that women are being excluded.
Various forms such as Lehrer und Lehrerinnen / LehrerInnen / Lehrer*innen / Lehrer_innen / Lehrer (m/w/d) are employed to show inclusivity.
(m/w/d) used to be just (m/w) to show that Lehrer (m/w) indicated "a teacher - of either male or female gender". Now that a third gender divers has been recognised by the government, many places use (m/w/d) after profession names to show that also people with that third gender mark in their personal documents are welcome to apply.
By the way, I just realised we seem to have something similar in German, but it refers to the title of "doctor" (= degree from university), not actually to the profession ("physician"). Mostly used by elder people, normally you would use their name.
"Ist die Frau Doktor / der Herr Doktor da?"
"Herr/Frau Doktor, mir geht es heute nicht gut."
Also used for university professors, and this is quite common: "Frau Professor(in) / Herr Professor, ich habe eine Frage."
I can't really tell, if you are intentionally offensive or just clueless, so here is the explanation:
There is no such thing as "lady doctors", because a "doctor" can be either male or female. As a consequence, using the additional term "lady" is considered highly offensive.
"Lady doctor", as you use it here here, is not a single noun. "Lady" is being used like it's an adjective to the noun "doctor". Not all professions in English have gendered versions. There's actor and actress, waiter and waitress, but there's only one word for "doctor" and that encompasses everyone. Both Arzt and Ärztin translate to "doctor." Especially in this sentence, where the speaker is talking about their sisters, it's unnecessary to specify further. "My sisters are female doctors" is redundant.