I'll be breaking down the Kabalarians definition first, so get ready for some blockquotes.
[...] Mitsuru gives you the desire for responsibility and takes you into practical pursuits. You could excel in accomplishments of a technical nature where concentration and attention to detail are important. Whatever you undertake, you have the patience and inclination to do well.
I've italicized points that I want to touch on, just for future reference.
This should go without saying, but this little tidbit is a great example of Mitsuru's responsibility and inclination for becoming the head of the Kirijo Group, so it fits very well! While Mitsuru isn't shown to have more of an affinity with technical professions like Fuuka, her outstanding excellence dictates she would do quite well in anything she does. I'm sure she'd be a great gal to call up if your computer stopped turning on, though I would probably still rely on Fuuka more.
The last statement of this quote references Mitsuru's ability to excel in absolutely anything and everything she does. Need something done properly? Call Mitsuru.
You lack sufficient spontaneity and fluency of speech, and are prone to make rather direct comments that are not accepted in the way you intend them. Nevertheless, you do have a strong sense of responsibility for the welfare of others and a willingness to be helpful.
Oh boy, can we talk about this!? Because this describes Mitsuru so well.
As talked about in the Personality section, Mitsuru has an inability to express herself properly because of her lack of interaction with people her own age, and also because of her very strict upbringing. She doesn't know how to communicate with others very well outside of a business or professional standpoint, which makes her seem incredibly standoffish and aloof. It makes Mitsuru very hard to approach, something Yukari addresses relatively early in the game. Her jealousy of her senpai quickly turns to hostility, when she senses Mitsuru may be hiding something very important from SEES. Due to Mitsuru's air of unapproachability, along with Yukari's fierce personality, it just doesn't end well at all.
While Mitsuru almost always has the best of intentions behind her decisions, she isn't able to communicate them well--or even at all--due to her rather blunt and sometimes harsh way of putting things. She's probably the last person you would seek out for comfort. She does, however, put the well-being of her peers, especially SEES, far above her own. Mitsuru feels a great responsibility to protect others, and is wracked with incredible guilt when she can't. This can especially be seen when the observational and analytical skills of her Persona start to dwindle upon reaching higher levels of Tartarus, and even moreso when her father dies. (More about that can be read over here.)
Now, as far as a simpler name meaning, I'll be using the kanji of her name to get more specific meanings. (Her kanji is 美鶴 for future reference.)
The first letter of her kanji 美 (bi, mi, utsuku.shii) means "beautiful, beauty", which is a great reference to the mature beauty that Mitsuru brings. There's actually a girl at Gekkoukan that will comment on how much a crush she has on Mitsuru, which is apparently common among both boys and girls at Gekkoukan who like her. So even in canon she's considered to be quite attractive and even has a fan club.
The second kanji of her name is 鶴 (kaku, tsuru) means "crane, stork", which could possibly be a reference to Mitsuru's height. She does wear high-heeled stiletto boots that give her an exaggerated feeling of tallness. While she is only 166 cm (5'5"), her boots give a boost to her height that really feeds the idea that she's quite tall. Insert "step on me Mitsuru" jokes here.
In a more literal sense: the crane itself is, in Japan, a mystical creature believed to live for 1000 years. In Japanese, Chinese and Korean culture, the crane is said to bring good fortune and longevity. The Japanese refer to the crane as the “bird of happiness”.