I dont know the situation so take my suggestions with a tablespoon of salt:
Diastolic HF is about fluid excess, salt, BP, obesity.
COPD is about smoking
My suggestions (if possible)
She and you have to decide to turn your life around. Not TRY but WILL
Main objectives:
1. Lose weight
2. Increase functional capacity
Understand that there is no shortcut. This WILL take time and effort and consistency and will be frustrating
Stop smoking (if she is)
Eat 80% of her food not 100%
Absolutely No soda, no juices: drink only water
Absolutely no snacking
Eat only baked or grilled food. Nothing fried
Minimize salt
Use oxygen for now. It will help her be more active
Use her inhalers as prescribed
Control BP
Start walking daily this way:
Day 1: see what she can do at her own pace, lets say it is 5 min (use walker if needed)
Week 1: daily walk 5 min
Week 2: daily walk 10 min
Week 4: daily walk 15 min and so on
Once you get to 30 min: increase the distance walked in 30 min
Follow this every single day with no days off
Things can be a lot different in 3 months
Good luck