Invitation letters from family also help: Your mum is looking forward to meeting her future daughter in law, mother of her grandchild etc...your brothers and sisters too. You have an income and prove it.
It's not nearly as hard as people say. Tick the right boxes, present a fat labelled file, evidence of relationship etc. You'll get it
Harder for me as my spouse is Cambodian and under 50....the embassy in Cambodia has indicated they won't issue a following visa with Non-O retirement, only education etc.