Child bonds

ClareC_3

I have two children and we are lucky enough to be able to save the total allowance in their CTF.
In addition we have invested in a child bond with Liverpool Victoria for our 2 year old, contributing £25 a month. We aim to let this mature when she is about 20.
We now have a 3 month old and I was about to get her a similar scheme but looking again the rates don't look so good.
It is tax free and all the schemes are heavily weighted for long term investment with big penalties for cashing in before 10yrs. However few of them give estimates of growth over a longer time scale ie 20years.

Are we making a mistake?

Thanks for any advice.
Clare