No. But you asked if there was a possible system to allow such (implying that you simply don't want to give one other your master password). I answered with one system I know of.
> I think it might be too difficult for mine to use as I did not find a nice gui or something for it.
They don't need a GUI as long as they can be trained (or better, step by step instructions on use provided to follow at such time as is necessary).
The wikipedia page I referenced, in the external links section, points to three implementations. None appear to have GUI's, so that either means:
1) you put together a GUI wrapping one of these for them
2) you put together detailed instructions on how to use one of the three to recover your access credentials when the time arrives.
Do you practice Shamir Secret Sharing with your relatives?
I think it might be too difficult for mine to use as I did not find a nice gui or something for it.