Cloning Fem Seed Plants

I'm having a terrible time getting any clones to live. The plant is a fem cheese and I'm wondering if fem seeds in general are hard to clone or it's just me.

I run Super Lemon Haze from a fem seed. It does seem that the first couple of times cloning that they take longer, but as the strain stabilizes, they seem to start easier. I would just take more clones than necessary and then pick the clones that root more easily and are stronger. I am on my 5th SLH grow from only one seed and they seem to root just as quickly as my other strains now. Hope this helps