A source close to Shepherd, 47, says the couple, who wed in 2011, were ill-matched from the start.
"I don't think any of us thought this was the right guy for her. He's a very nice man, but he can't keep up with her. She is a force of nature. The girl works morning to night," the source says of Shepherd, who has juggled The View with long-term side gigs on How I Met Your Mother and 30 Rock.
"She needs somebody that's her equal emotionally, intellectually and financially – and that's hard to find."
The fight is getting ugly fast: Court documents show Sally, 43, wants full custody of the unborn child, who the papers say will be named Lamar Sally Jr., and he's also seeking spousal support and the invalidation of their prenup. (According to a report, Shepherd countered with her own filing, asking to enforce the prenup but not addressing custody.)
"I really can't say anything," Sally told PEOPLE, adding that he has lost 50 lbs. "on the divorce diet."
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