She's been isolated most her life so it's very difficult and would take some time!
Once she starts to trust Rose, the only way she'll feel comfortable to initiate something is if Rose has done it first.
Rose held her hand? Will slowly hook a finger around Roses finger and working her way up to proper hand holding
Rose gave her a smooch? Juni will start off with cheek kisses until she doesn't feel like she'll explode if she kisses Rose on the lips.
Sex though take Juni a loooooooong time to ask for straight up for it. She'll try roundabout ways, while as red as a tomato.
Rose knows what's going on, and thinks Jujinis so darn cute she'll play dumb just for a little bit just to see Juni be all cute