Ive still not invested Lucy's

I know Im bad, but life is just a bloomin whirlwind for the past few months.
Rebecca's is onvested with HBOS-a stakeholder thingy, I am clueless.
My question is, can I invest the voucher in a straight forward bank account as I dont want to be part of the stocks and shares market (with the state of this country at the mo) so she just gets back what I pay in?
Or should I keep her the same as her sister? As I dont want one ending up with a wedge more than the other.
I pay £20 in a month for rebecca but cant afford to do the same jst now for Lucy as Im on no pay and need to wait til I return to work in Spet.
ahhh decisions decisions x