Grouping with someone and effects on quests

My wife and I have just purchased Guild Wars and most of the time we adventure together, therefore do the same quests together. However, sometimes there's 1 or 2 minor quests that we'll do on our own before joining back up again. What I've noticed is that some quests that my wife does, does not show up for me. Is this because once one of us completes a quest on our own and then we regroup, the game marks that quest as completed for me also, even though I never did it? Therefore grouping up with someone will make it so you cannot do any of the quests that they have already completed?

some quests are for some professions only :P

Yes, I realize that myself being an E/N will not be able to do some of the quests that she (being a W/E) is able to do. One example of a quest, which according to the WIKI is for everyone, was the 'poor tenant' quest. She completed that one on her own, but I was never given the option by Miller Upton to start the quest. I assumed that once we regrouped, the game considered the quest completed by my character as well.

The game will not link quests to parties unless you all start the quest at the same time.

If you were both on the map at the same time, but in diff locations when she did the quest you might have such a problem. But if you were not on the map at the time she did the quest then it will be available for you when you zone to a city and enter that map again.

Remeber unless your writing them all down it can be easy to forget what quests youve already completed and collected the reward for.

Lastly some quests are campain specific, so if her char is Canthan and yours is from Tyria you may not be able to do the quest.

http://gw.gamewikis.org/wiki/Poor_Tenant says you get the quest from Namar in Ascalon City. Did you have the quest available in your log when you talked to Upton?

There are quests that one person in a party can have that can make it impossible for another member in the party to get or do another quest. But the wikis usually warn about that and there's nothing like that listed for this one.

If you had the quest in your quest log though, then I don't know why it didn't work for you.

If you did not have the quest in your quest log, then you have either done the quest already, or you need to talk to Namar to get it first, and then talk to Upton.

Other than that, I have no more suggestions other than to maybe try contacting support.

Also remember that some quests require the completion of others, so be weary of that if you decide to split and she has a quest that you havent done the prerequisite for.

So, to answer your basic question - no, the game does not mark quests done by others as being done by you.

Think about it - if that happened, all you would need to do would be to group with someone who's done all the quests and presto!, you've done them all too.
As has been said - some quests require that you do other quests first, some are only for certain classes and/or secondary professions.
At the top of the description of a quest (in the quest log when you press "L") it will say who you get the quest from. As has been pointed out, you get the Poor Tenant quest from Namar in Ascalon City.

You only get credit for quests you've actually done yourself - whether in a group or solo.

Btw, you appear to be in pre-searing. There you can only have 2 people in a group, but later in the game you can have 4, then 6, then 8 (and a few elite missions with 12).

I'd point you to Wiki for help with quests, but I think Wiki can kinda spoil the sense of adventure, especially if you use it too early. Just say NO to Wiki!