Here's a video of Dodie Osteen's testimony. From the things she says it's clear she's mixed New Age hocus-pocus with her Christianity. At one point (starts around 26:30) she says she visualized pictures of herself when she was younger riding horses and in her wedding dress. She says when things "came against her" she'd remember the pictures.
She also uses Romans 14:7 to say we have the same authority as God to call things into existence from nothing:
"(as it is written, 'I have made you a father of many nations' ) in the presence of Him whom he believed—God, who gives life to the dead and calls those things which do not exist as though they did;" This passage is talking about Yahweh, not humans. A typical example of Word Faith scripture twisting.
At 26:35 she talks about a "contract" she made between herself, her husband and Jesus. Of course Jesus couldn't sign His name so she signed for Him. It was a "long list of things she wanted." This too is little more than positive affirmations put in writing, a very common practice for New Agers and practitioners of magic.
In all fairness she does talk a lot about prayer and scriptures, but as we've seen her understanding of scripture seem influenced by her New Thought and New Age beliefs. Did James say we should say positive affirmations or do creative visualization? Not hardly:
"And the prayer of faith will save the sick, and the Lord will raise him up."
All we have to go on is John and Dodie Osteen's word. This, coupled with the fact she's clearly a false teacher, makes it plain to me she's not to be believed.