Congrats!
My thoughts on your names:
[name_m]Maxwell[/name_m] - I do like this name, he feels handsome and has a cool all-American-boy sound. So because of this, I find that [name_m]Maxwell[/name_m] feels, a little off with [name_f]Harriet[/name_f], [name_m]Joseph[/name_m], and [name_f]Abigail[/name_f], as this sibling set sounds so British.
[name_u]Elliot[/name_u] - I agree too close to [name_f]Harriet[/name_f].
[name_m]Samuel[/name_m] - A lovely biblical classic. He has a soft, handsome sound and looks really sweet. I love the [name_u]Sam[/name_u] nickname! [name_m]Samuel[/name_m] also works with [name_f]Harriet[/name_f], [name_m]Joseph[/name_m], and [name_f]Abigail[/name_f]. The names sound great together.
[name_m]William[/name_m] - [name_m]Ah[/name_m] a lovely regal classic! [name_m]William[/name_m] sounds lovely, has a very classy vibe and is rich in history. I love the nicknames for [name_m]William[/name_m] as well [name_m]Liam[/name_m], [name_m]Will[/name_m], [name_m]Bill[/name_m], [name_u]Billy[/name_u], and [name_m]Wills[/name_m]. He sounds so perfectly British with [name_f]Harriet[/name_f], [name_m]Joseph[/name_m], and [name_f]Abigail[/name_f].
[name_m]Oliver[/name_m] - I really love the name [name_m]Oliver[/name_m]; it’s handsome, demure, and has a lovely elegant sound. I also love the [name_u]Ollie[/name_u] nickname. [name_m]Oliver[/name_m] works with [name_f]Harriet[/name_f], [name_m]Joseph[/name_m], and [name_f]Abigail[/name_f].
[name_m]Edward[/name_m] - A lovely name, feels so retro and cool teamed with [name_f]Harriet[/name_f], [name_m]Joseph[/name_m], and [name_f]Abigail[/name_f]. I love the [name_m]Eddie[/name_m] nickname as well. It just works.
[name_m]Matthew[/name_m] - Hmm I do like [name_m]Matthew[/name_m] it’s a fine name but feels slightly beige…
Suggestions:
[name_m]Christopher[/name_m] ‘[name_f]Harriet[/name_f], [name_m]Joseph[/name_m], [name_f]Abigail[/name_f] & [name_m]Christopher[/name_m]’
[name_m]Lysander[/name_m] ‘[name_f]Harriet[/name_f], [name_m]Joseph[/name_m], [name_f]Abigail[/name_f] & [name_m]Lysander[/name_m]’
[name_m]Vincent[/name_m] ‘[name_f]Harriet[/name_f], [name_m]Joseph[/name_m], [name_f]Abigail[/name_f] & [name_m]Vincent[/name_m]’
[name_m]Theodore[/name_m] ‘[name_f]Harriet[/name_f], [name_m]Joseph[/name_m], [name_f]Abigail[/name_f] & [name_m]Theodore[/name_m]’
[name_m]Miles[/name_m] ‘[name_f]Harriet[/name_f], [name_m]Joseph[/name_m], [name_f]Abigail[/name_f] & [name_m]Miles[/name_m]’
[name_m]Robert[/name_m] ‘[name_f]Harriet[/name_f], [name_m]Joseph[/name_m], [name_f]Abigail[/name_f] & [name_m]Robert[/name_m]’
[name_m]Leonard[/name_m] ‘[name_f]Harriet[/name_f], [name_m]Joseph[/name_m], [name_f]Abigail[/name_f] & [name_m]Leonard[/name_m]’
[name_m]Zachary[/name_m] ‘[name_f]Harriet[/name_f], [name_m]Joseph[/name_m], [name_f]Abigail[/name_f] & [name_m]Zachary[/name_m]’
[name_m]Timothy[/name_m] ‘[name_f]Harriet[/name_f], [name_m]Joseph[/name_m], [name_f]Abigail[/name_f] & [name_m]Timothy[/name_m]’
[name_m]Nathaniel[/name_m] ‘[name_f]Harriet[/name_f], [name_m]Joseph[/name_m], [name_f]Abigail[/name_f] & [name_m]Nathaniel[/name_m]’