I think you've hit the nail on the head when you say that Isla is more trendy. They are all relatively popular, all within the top 100 but Isla markedly more so and, while it has been popular for a good 15 years, sort of came from nowhere, whereas the others are definitely more classic. If you look at the stats:
Isla is currently number 3, with 43,100 born over 15 years (from 2006 to 2021, the latest year we have data for)
Lucy is currently number 85, with 29,225 born in the same period
Hannah is currently number 89, with 22,862 born
Rose is currently number 68, with 12,161 born
That being said - they are all beautiful names and only you can say if popularity or trendiness is important to you.