You're right, your colleague is wrong. "Why am I got up today" makes no sense. Also possible:

Why have I gotten up? (AE)
... got up? (BE)

In addition you can say what you suggested: Why did I get up today? (Meaning: Why didn't I just stay in bed?)

(Incidentally, it's "Hi, everybody/everyone!" ;-))

I think the present perfect is unlikely in practice.

I agree with dude and SD3 - with a preference for SD3's version - for what is evidently the meaning: "why didn't I stay in bed?"

Just for the sake of completeness - and hopefully not leading anyone astray - the collocation "all got up" does occur with the meaning that someone is dressed in finery. I understand it as either regional (heard it from my Midwestern relatives) or (self) deprecating/jocular. The related noun is "getup". Merriam-Webster lists the following:
2 to arrange as to external appearance : dress
Example: all got up in her Sunday best
http://www.merriam-webster.com/dictionary/get%20up
http://www.merriam-webster.com/dictionary/get... (for noun)
So, "why am I got up" could mean "why did I dress up today?" - except that I would expect "why am I all got up" - but perhaps this is why your colleague thought the phrase sounded all right.

(BTW, according to Webster, both spellings are acceptable, though "all right" is more common.)

#4: the collocation "all got up" does occur with the meaning that someone is dressed in finery.

Yes, that's what I thought of when I first saw the thread :-)

Also, just in case any English learners read this thread, it would be more idiomatic to phrase part of your query differently.

I read this sentence by (from) a colleague and discussed it with her (about it) - She thinks (thought) it's alright.

Other options are correct, too.

...and talked about it with her. She thought it was alright.

@6:

As an English learner, I have to ask:

Shouldn't that be "all right"?

;-)

#4/5: the collocation "all got up" does occur with the meaning that someone is dressed in finery.

that's what I thought, too...

@Woody 1:

No, alright is alright, meaning OK. 'All right' means rather 'correct in all particulars'.

OT:

I'm not sure I get the distinction made in #9. Traditionally - in BE at least - "alright" has been frowned upon, AFAIK.

OT
On the subject of "all right"/"alright" MW has the following:

Usage Discussion of ALRIGHT
The one-word spelling alright appeared some 75 years after all right itself had reappeared from a 400-year-long absence. Since the early 20th century some critics have insisted alright is wrong, but it has its defenders and its users. It is less frequent than all right but remains in common use especially in journalistic and business publications. It is quite common in fictional dialogue, and is used occasionally in other writing (the first two years of medical school were alright — Gertrude Stein).
First Known Use of ALRIGHT
1887
http://www.merriam-webster.com/dictionary/alright

OALD has:

alright
adverb
alright pronunciation English ɔːlˈraɪt alright pronunciation American ɔːlˈraɪt
(informal)
 
= all right
Help
Some people consider that this form should not be used in formal writing.
http://oald8.oxfordlearnersdictionaries.com/d...

Thank you for all your answers! This feedback is stunning!

Regards
Cinderella

#12: This feedback is stunning!

You're welcome - and we are simply stunning people! ;-)