There's not much out there to research because they haven't produced much. The company formed in 2015 and states that it puts out 3-5 manuscripts a year (although there are only eight books listed in their website catalog).
Reading between the lines of their FAQ, it appears that they're like most small trade publishers: run mostly by one person (who, per her LinkedIn bio, has no publishing background) with design and editing farmed out to contractors, decent availability via online merchants like Amazon and Barnes & Noble but no brick-and-mortar bookstore presence, no advances, promotion mostly limited to providing ARCs, virtual book tours and a couple of giveaways, and the suggestion that they lean heavily on the author's social media platform for much of their visibility.
Small trade publishers can be a
very mixed bag. The problem with most of them is that they're under-capitalized and under-staffed. Very often this leads to the publisher struggling to make ends meet, and eventually folding. Check out the
Publisher Index of this sub-forum. All the grayed-out names are publishers that are no longer in business.
It's a good sign that this niche publisher isn't putting out books willy-nilly, but with their limited marketing and distribution, my guess is their sales probably aren't great, either.
P.S. I had a quick look on Amazon at one of their recent (in fact, their only) YA books and it has one glaring formatting issue: chapter headings don't start until Chapter Three (i.e. there is no Chapter One or Chapter Two). Someone at Little Lamb isn't paying attention.