@glall2u2 It would be reasonable for your neighbor to look for new housing if they aren’t satisfied with where they are now.
Have your child avoid wearing tennis shoes or hard shoes in the house, use socks or slippers with rubber bottoms to help prevent slipping. The alternative is very soft soled shoes like moccasins.
Don’t let your child jump off furniture. It’s fun, but loud downstairs. When your child plays with hard toys, try to keep them on the carpet or rug (or a rug on top of carpet, even better) for sound management.
Other than these basic guidelines, you’re doing a good job. It’s your neighbor’s responsibility to deal with basic kid noise, not yours.
When winter comes, you bundle up, and go outside. Warm drinks in a thermos help a lot. Dress in layers that can be stripped off as she gets hot, and replaced when she is finished playing so she doesn’t get chilled on the walk or ride home. Buy mittens, not gloves, and buy a few pairs that are identical. When you lose one mitten, you have backups to replace it. Buy mitten clips or strings to help keep them from getting lost. They will still get lost, but not as soon. In a desperate situation, put cute socks on her hands to stay warm. If she gets cold, then put her in a warm bath when you get home.
When kids of any age get and stay fussy, put them in a warm bath even if it’s not bath time. Never leave them alone in the bath, not even for a second.