The Benefits of a Lifetime ISA

My wife who is 34 is planning to go self-employed soon through setting up her own business. She has been all too enrolled into her current work pension and has only ever paid the minimum amount plus never really given it much attention. Can I ask what would be the best option? Either an ISA with regular investments in a global multi-asset fund or setting up a pension into the same fund. The ISA on paper is more appealing given that she'll be able to access the money without restrictions unlike a pension. However, I know whether pension does bring tax benefits. As a side point, would a lifetime ISA be considered a good option? A law again aware of the