More than that: the standard morning greeting is בוקר טוב, and בוקר אור is the standard answer. I believe this matches the Arabic standard (at least the Palestinian dialect) word for word. I guess (though not sure) that modern Hebrew coined it based on Arabic - and I'm very curious when and by whom. Hebrew borrowed a lot of slang from Arabic, but sadly not a lot of standard/polite speak.
Check out YouTuber Linguistix, just search linguistix resh, for how to pronounce, if you can't hear it then https://fluent-forever.com/how-to-learn-pronunciation-anki/ explains why and what to do.
Not the same (and "valid" can have different levels). I can imagine a fancy state of the world, and an idea I want to get across in this fancy world, where my most natural choice of words in English would be "I don't think my monkey is a good secretary". Can you imagine an idea you'll want to get across where you'll choose "pretty morning"?
oops, just noticed that the sentence here is בוקר יפה and not בוקר טוב, so my first comment is a bit irrelevant. As yuval wrote, you can get most adjectives for feminine by appending the ה to the end of the verb. However, notice that יפה is an example for an adjective that is written the same for both genders, but pronounced differently: Yaffe for masculine and Yaffa for feminine.