She wrote a letter and sent it. (past simple)
She will write a letter and send it. (future simple)
She would write a letter and send it. (fp)
She is writing a letter and sending it (pr. cont)
She was writing a letter and sending it (past cont)
She will be writing a letter and sending it (fut. cont)
She would be writing a letter and sending it (fp)
She has written a letter and sent it (present perfect)
She had written a letter and sent it (past perfect)
She will have written a letter and sent it (fut. perfect)
She would have written a letter and sent it (fp)
She has been writing a letter and sending it (present perf. cont)
She had been writing a letter and sending it (past perf. cont)
She will have been writing a letter and sending it (fut. perf. cont)
She would have been writing a letter and sending it (fp)