Answer:
She said that it was a fine weather for picnic.
Step-by-step explanation:
Reported speech is used to communicate what someone has said. It consists in going back one tense and modifying other words, such as pronouns, demonstratives and time expressions. In the example sentence, even though the quotation has no verb, it is assumed that she is referring to the weather at the moment of speaking. As a consequence, from a Present Simple tense, the reported statement changes into the Past Simple tense: was.