Optimizing my moms retirement income.

Was going through my moms(f83) accounts and trying to optimize stuff

For her income she is making 80k , 20k cpp/oas , pensions 50k (~8k rif , rest is her pension and late dads pension ) 10k of interest .

For assets she has 500k with 125k in tfsa and 110k in rif. The rest is non reg. Most of her investments are in cash hisa but a few stuff in market. She is convinced stock market is overvalued so reluctant to put much more money into that.

She spends much less than she earns for nw has gone up from 330k -> 500k from 2020 to 2026.

I was thinking that we should be divesting the rif faster than the current rate. Is there any considerations I should have for that? She has the dental plan thing and would like to keep it. So would I be able to increase income from rif to around 89k . Is there any downside to that?

Also I was thinking to use dividend investments rather than hisa to save on taxes. Is that reasonable. Wasn’t sure what is stocks / etfs are optimized for Canadian dividend taxes.

Is there anything else I should be considering? Anything I should be reading ?