It's better if you can make a well-formed English sentence first. The examples you gave aren't very clear in English either. And they will be just as confusing in Japanese.
In any case, it's usually just a matter of chopping up the sentence into its component parts and rearranging it in the reverse order from English.
She said she wants to talk to you about that day when her mother
talked to your mother about what they should say to their children.
about what they should say to their children
--> kodomo ni iu beki no koto ni kanshite
about that day when her mother talked to your mother
--> kanojo no haha ha anata no haha ni hanashita hi ni
She said she wants to talk to you
--> Kanojo ha anata ni hanashitai to iimashita.
So we get something like:
Kanojo ha anata to kodomo ni iu beki no koto ni kanshite kanojo no haha ha anata no haha ni hanashita hi no koto wo hanashitai to iimashita.