how to raise the rent without scaring the tenant

[Twannisha Jackson]

just bought a property, inherited a tenant. very nice property, side by side. 1bd 1ba. she has been there for over 10+ years, maybe 15. she pays $475. the lowest rent surrounding is $775. I want $850. mortgage is $1,200. I’ll cover the rest. she’s aware of the rent increase when I take over. she’s older woman late 40, early 50. not even sure how to price this. suggestions?