I forgot to mention that all 10 family members – 2 parents and 8 children – are included in the 1900 US census. The parents (under the names Louis and Fanny Weinblatt) and the 4 youngest children were in Brooklyn and the 4 older children living with spouses and American-born children in their own households in Brooklyn (Mary) and Perth Amboy (Max, Dora, and Tillie).
Also, I thought it might be useful to share the article – the 1918 death notice for Mrs. Samuel Belikove – which provided my first big breakthrough in discovering the wider Weinblatt family. Note that there is no mention of neither a mother (Fannie had passed away in 1915) or a brother Isaac (who can't be found in any records after 1900).
Again, thanks for any help or pointers you can share. Feel free to respond to me privately as appropriate.