Jay Leno's Wife Has ‘Good and Bad Days’ Amid Dementia Battle, TV Star 'Vows to Look After Her'

Jay Leno is devoted to his wife of nearly 44 years in sickness and in health.

Last month, the late-night talk show host, 73, filed for conservatorship over his wife, Mavis, 77, noting she "lacks the necessary capacity to execute the estate plan" due to "major neurocognitive disorders (including dementia)."

Now, a source spilled "Jay has been wonderful" with Mavis throughout her health battles.

"He takes care of her. He gets her out of the house, which she seems to respond favorably to," the source continued. "It’s a difficult situation, as anyone can imagine."

In the television personality's legal filing, he said he'd been in a "loving marriage" with Mavis for more than 43 years and he's "always handled the couple's finances" in the past.

"Unfortunately, Mavis has been progressively losing capacity and orientation to space and time for several years," the court documents read. "Jay is fully capable of continuing his support for Mavis’s physical and financial needs as he has throughout their marriage. Jay desires to execute an estate plan, including a revocable trust and will, which will provide for Mavis and Mavis’ brother and her sole living heir aside from Jay."

Attorney Christopher C. Melcher explained the couple currently have a "living trust in a will" that was created before she was diagnosed with dementia.

"Jay is concerned about is that he might die before she does, and somebody is going to need to take control of these things," Melcher said. "So, he's just trying to do that planning now, and he needs a court order to rearrange their affairs because she has dementia and doesn't have capacity to agree to anything right now."

The source told a news outlet that the legal move "seemed like the prudent thing to do," given their situation. But despite Mavis' health struggles, their relationship remains strong, per the source.

"Mavis was always Jay’s rock and now he must be hers," they shared, noting she's been forgetting things and have lapses in short term memory lately that make her life more difficult. "She’s been unable to handle day-to-day tasks."

"To see her decline like this is tragic — she has her good and bad days — but Jay’s been wonderful," the source added. "He vows to look after her so long as he has breath in his body. He won’t let her down."

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The source spoke with Star magazine about Jay and Mavis' relationship.

Fox News Digital reported Melcher's comments about the television host's conservatorship petition.