If you cheat a little, you can get to similarly low numbers in German:
"Zuviele Abschiede von ihr" - 8
"Ihre zuvielen Abschiede" - 8
"[Sie] verabschiedete sich zu oft" - 8-9
If you accept "trennen" ("separate") for "saying goodbye", you can do
"[Sie] trennte sich zu oft" - 5-6
If you accept "[weg]gehen" (go [away]) for "saying goodbye", you can also do
"[Sie] ging zu oft [weg]" - 3-5
The "Sie" (she) is optional, but leaving it out sounds hurried and informal.
The literal translation also isn't very idiomatic imho, I'd rather expect to hear one of the latter ones if it was really about separations and going away, the former phrasing suggests more something of literally saying too many greetings.
More like "Sie verabschiedete sich zu viele Male zuvor" (literally, "she farewelled too many times before", but acceptable to a native speaker).
And no, you can't omit "sie", German is not a Romantic language and the pronoun is required even if the verb has to match it by case anyway.
I'd say your examples are more than "a little" cheating. Most of these are incomprehensible or completely fail to deliver the same idea as the original. You can truncate sentences in poetry but at some point you just end up with disjointed fragments.
"Zuviele Abschiede von ihr" - 8
"Ihre zuvielen Abschiede" - 8
"[Sie] verabschiedete sich zu oft" - 8-9
If you accept "trennen" ("separate") for "saying goodbye", you can do
"[Sie] trennte sich zu oft" - 5-6
If you accept "[weg]gehen" (go [away]) for "saying goodbye", you can also do "[Sie] ging zu oft [weg]" - 3-5
The "Sie" (she) is optional, but leaving it out sounds hurried and informal.
The literal translation also isn't very idiomatic imho, I'd rather expect to hear one of the latter ones if it was really about separations and going away, the former phrasing suggests more something of literally saying too many greetings.