`1` ,

`->` She last ate fish was 2 months ago

`->` The last time she ate fish wa 2 months ago

`2`, 

`->` We last saw her was a week ago.

`->` The last time we saw her was a week ago 

`3`, 

`->` We last met each other was when we graduated

`->` The last time we met each other was when we graduated 

`4`, 

`->` It last rained was 4 months ago.

`->` The last time it rained was 4 months ago.

`5`, 

`->` Mc Alista last cooked was when he was sick

`->` The last time Mc Alista cooked was when he was sick

Bonus:

S + haven't/hasn't + P2 + O

= S + last + V-ed + was + (time) + ago / when + (time)

= The last time S + V-ed + was (time) + ago / when + (time)

$\text{#BTS}$