I didn't want to actually post the comment, in fear of offending you in front of your friends or something, but it was too good to pass up so I screen capped my hilariousness:
its over man...ever since she started being featured in bigger things other than AOTS...she really does give that stuck up vibe...she used to be funny...not no more
1) When you first board the Normandy, you should directly talk to her. Your first choice in dialog should be "The pleasure is mine"
2) After that, you should chat with her. Following the "what do you do here" option you should choose "Is that all", "So you're a councelor" and last "It's good you are here" . Following the cerberus option , choose "does cerberus hate aliens" and then "you are very loving". Following the "are you happy here option" , choose "we won't" and then "i'd embrace you". That should be enough to trigger the romance options for the rest of the game. After you've done this, go talk to someone else (jacob preferably) and then go back to Kelly.
3) She will ask you if it bothers you that she was informal, tell her you liked it. [edit] Post-Recruitment Conversations
Note: Somewhere in either Act II or Act III Kelly will say she wished you two had time to talk more. Say "Let's have dinner". After dinner she will ask you if you want her to feed your fish. Whatever you choose may not affect the ending, but saying "Yes" is better safe than sorry. [edit] Act II
4) After you have done the mission for Garrus, talk to her, tell her you worry about him , and the "I could use that too"
5) After you have recruited Jack, talk to Kelly, ask her "what do you mean" and then tell her you'll be carefull
6) After you have woken Grunt up talk to Kelly and tell her you'll protect her.
7) When you're back from Horizon , tell her "It went well", "That's history", and thank her. [edit] Act III
8) After you rescue Thane (other characters may trigger this conversation too), select the choices "Maybe both", "That's not my thing".
9) After you get Samara, tell Kelly she is prettier.
10) After you rescue Tali, talk to Kelly and follow these options "I do too", "How so?", "Are you into aliens?". This is when Kelly lets you know she's bisexual.
11) After the Collector ship talk to her and say " Worried? You do care." and "What about me?"
And that should be the end of the conversations you can have throughout the game. Note that this is not necessarily the order in which they will occur as you may choose to do the missions in a different order. But don't choose differently when talking to her. Also, I haven't mentioned some occasions like, what to do after Mordin's mission, or when you get Grunt on board the Normandy because you don't even get to say anything. [edit] Act IV
In order to complete this, you must instantly go after the Collectors after they kidnap your crew, or Kelly will die. And God will kill a lot of kittens as well. And you don't want that to happen. You also don't want Krogans to charge at you.
Obviously, while in the Collector base, send someone with the crew to get them back to Normandy. You should also make sure YOU don't die during the mission. Have Garrus/Miranda/Jacob for fire teams, Tali/Legion for the pipe thing and Samara/Jack for the biotics shield. If you do that, no one will die. [edit] Epilogue
When you finish the game and credits roll, click continue. You should be in your cabin. Get down to the CIC and talk to Kelly for the last time. Ask her if she is okay. Then save the game and load it (quicksave is fine). Go to your computer, the infamous letter will be there. Go up to your cabin and call her up through the computer between your pc and the achievements file. Voila!
