The Gang's All Here

Neena becomes available at 69 40 in Maldraxxus, near the cave between Glutharn's Decay and House of Rituals, on the Decay side.

Requires Stitchyard Level 2 for the player to see her spirit, she will be trapped in the cage. The nearby lich will drop a key for her.

Her Construct Ability is a looterang, she has a few passive abilities the player does not have control over. A stacking 5% health bonus for her and the player maxing out at 25%, as well as a charge that knocks enemies around a bit.

Miru Snowblossom is available to create at level 1 of the stitchyard. He is available after a short quest in Maldraxxus at the House of Constructs.

He is in a underground building (entrance 24.67, 31.70) from the entrance, head straight back.

Kill the required mob nearby and return the quest. He appeared at the table shortly after.

Requires 20 Malleable Flesh to craft.

Miru Snowblossom available from lvl1 stitchyard.

Originally located in undeground building at the House of Constructs (32.98 32.84).
For opening his jail, go to (58.63 35.66) and pull the 'Cell Portcullis Chain'.
Get his quest, kill Bacilia The lost Soul (67.62 15.53) and retirn quest to Miru.
He will appear for crafting (20 Malleable Flesh) at your Stitchyard shortly.

Special Thanks for @Nickorvis and @Sortul.