Brow tint reaction but lashes fine?

[SamSpa]

I had a lash and brow tint client due on Saturday morning but after half an hour she still hadn't turned up, I text her to check she was still coming and she text back saying that last time I tinted her she had an eczema like reaction on her eyebrows but could she leave her appointment booked in for her lashes in November - I text back saying that I would not be happy to do her lashes as if she has reacted on her brows, her lashes could react and that would be much worse, I suggested doing another patch test before doing anything but to be honest the whole thing has left me a bit puzzled. I used brown on her brows but blue/black on her lashes, would the colour have made any difference? What I really need to know is if anyone has ever experienced this before and what you would do, she never replied to my text so I'm not really sure what to do now! :|