The Creator did not make an appearance at the beginning of the LC, so he did not even bother to waste time on her and is apparently getting ready to do battle with LF.
If you recall TPTP ending, where the Creator and Covenant have a "talk"
The Creator said he took a big chance in contacting TC. He didn't contact Covenant directly in the Second Chronicles for the same reason. We don't really know whom he contacted or if he hasn't. That has never been told. (but she was given a hint by Jeremiah)
But she will be shocked to learn that Jeremiah long ago chose the Land, and Croyel, over her, and that he is no victim but, in his naive, innocent way, one of the villains.
There is no indication that Jeremiah has chosen anything. He may be the pawn with an ability within the Land. He is controlled by a croyel (Whom Foul has set in place - [debates on croyels really havn't been discussed here -abilities, what they really can do]) He looked the same to Linden when she revealed the truth, in the Land and in her real world. So we do not have a the answer on Jeremiah choice.
LA should have tried to put a stop to the Ceasures by putting a stop to Joan, undoing the mistake she made by putting the wedding ring back on her finger.
Putting the ring on Joan was successful therapy. It reduced the amount of damage Joan did to herself, as well as the amount of hysteria Joan displayed. Even Donnelson said he would have made that mistake 12 out of 10 times. (From the Donnelson's GI)
Trying to stop Joan would be paramount undertaking. The most likely place she is at, is in the Sandgrave. So is the Lurker, whom may be the one watching over Joan so Linden can't approach her. At the end of FR, Linden doesn't have the power that a envenon TC had when he faced the Lurker. It was near the end of RoTE that Linden had proof that Joan was behind the ceasures creations. There really wasn't enough time to enlist the needed help to fight the Lurker. If she would have tried to convince the masters to stop Joan, she would have been distracted because of Roger and a Croyel controlling Jeremiah showed up and wisked her away. If they didn't show up, and she convince the masters of the noble task, then she would have never learned the seven words, the staff would have not be completed and never transformed by the earthblood. The Lurker would have overwhelmed her. She is still not powerful enough or have the lore to handle the Lurker. Add in Kevin's Dirt and Esmer, then you can see the obstacles she faces.
She used her one shot at the Power of Command to uncover a truth which should have been obvious to her anyway, rather than focusing on Joan. But LA is too blinded by her immediate feelings and immediate needs to think about others or the Land's problems.
She's a doctor, she is used to dealing with facts (truths). So she used the one power that allowed her to see the truths. {It's also debateable that she may have an ability to see certain truths which her Power of Command has given her. It still may be active - but that a debateable issue} She saw Jeremiah and the Mahdoubt confirm that Foul has control of her son. That is her needs and her feeling for her son is solid. She has a faint hope of saving him. She doesn't like Foul, (she will not forgive for what he has done to her son)
As for others.. have you read "Tales Among Friends"? She deeply cares about her friends. Plus her lashingout at the Harrow because of the costs shows she deeply cares.
As for the Lands problems, well, if she didn't care, she would have nevered healed it from the Sunbane. She has got a whole lot of her life and experience tied into the Land.
She knows she dead in her world, she trying her darnest to make the Land a place where she can grow old in.
She really hasn't been in the Land that long. She has done a number of remarkable feats in a very short amount of time.
Raising TC back from the dead was to abolish the constraint placed on him. The dead weren't allowed to speak to her. So she took took the dead away from the constraint. She needed TC. He is the only one who she will defer to. (or so we shall see in the next two books)