Burning genealogy questions

I'd like to answer these in my lifetime:

Our Indian Princess LH54-M9M
Who was Mary (Scott? Mathiot?) Mendell (1800-1850), and what was her Native American connection? Wally's stories say there was a legendary Indian ancestor and she's the only candidate--some family records say she was born in Nebraska, but others Pennsylvania. DNA research has been inconclusive (despite early matches to Long Crane Chocsaw, later updates have taken those away), and researcher Ryan Englund didn't find her parents/maiden name in his 2016 documentation. Is that really her photo?

Lost in Prussia 27S7-5GG

Catherine Hilligan (1811-1897)'s German family/origin details. Researcher Stephen Wendt in 2021 found no conclusive info but possible leads to Nellinghof/Oldenburg, Germany. Relative Richard Kajma has leads to the Vossbrink in-laws and Kregers from Gehrde, Germany. Waiting for more records to be digitized to find these answers.

Matrimonial Mystery KNQ4-W68

What happened to Mahala Billings Cottam, John's reported wife? Mahala appears to have been the only child of Timothy and Rhoda, and she left her widowed (or deceased?) mother in England to cross the plains to Utah in 1862. Arriving in September, she married British pioneer John Cottam as a plural wife a few months later in 1863. However, she then vanishes from the family and other records, can't find her in any Utah sources, but a Mahala Cottam died in England in 1865 so it's possible she went back to England and died there.

The Forgotten Treasures LV6J-DNY

Where is the Cramer family Bible I've seen xerox copies of? And Hiram Cramer was a prosperous shop owner who died in 1909, where are his photos?

Clues to the Scarborough Second Family G919-KGV

After Elizabeth left John in England, he remarried (and named his first two children after the two he'd lost to America). Tracking down John Scarborough's second family has taken years, but I've found a lot of details about Ellen and their children Joe, Annie Baynes, Albert, and Nellie Robinson, and their five grandchildren (so far). He died in 1908, where is his photo?

The Missing Son L1FX-2FR

What happened to Thomas Grover's Nauvoo wife and child, Betsy and Joseph, who didn't go west? Joseph was born in 1845. Can't find them.

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These questions will probably have to wait until we meet them on the other side:

Who was Hezekiah Hatch's Nauvoo fiancee (he died on their intended wedding day)?

Why did Hannah Grover leave Thomas, father of her 15 children, for a plural marriage with Daniel Wells in her later years?

What was Victor Hegsted thinking with those post-Manifesto polygamous wives?

Why did Joseph Billington leave Utah to return to Iowa with the RLDS community?