Helpmate
/ˈhelpmeɪt/
Definition 1 of 1
Pro Tip 1/3Marital Support
Often refers to a spouse offering support and companionship through life's challenges and goals. 
At the award ceremony, he thanked his wife for being his steadfast helpmate.
Pro Tip 2/3Beyond Romance
Can apply to non-romantic relationships where strong support and partnership are present. 
My business partner has been a true helpmate in growing the company.
Pro Tip 3/3Emotional Bond
Implies a deep emotional connection, not just a functional or practical assistance. 
Her sister has been more than family; she's a devoted helpmate in times of sorrow.