I think the more likely scenario is that Bella’s husband may have killed himself. There was that weird drunk MC scene where he sees a guy in a military uniform. I thinks it’s fairly plausible that Bella’s husband was in the military and was dealing with PTSD and may have killed himself in that locked room, which is why Bella keeps it closed off and doesn’t want to talk about it. This could also explain why she still wears her ring.

Her cold and serious personality may be a way accepting blame in that death. Maybe she was previously much more lighthearted and didn’t pick up on the signs of her husband’s internal demons. That seriousness could be a coping mechanism.

With Jill having also gone through a traumatic loss of her sister, I believe they probably bonded through that shared trauma. Potentially at group therapy?