"she is an extremely voluble young woman who engages in soliloquies not conversations"
is similar to
full of trivial conversation
"kept from her housework by gabby neighbors"
see also
able or tending to communicate
"was a communicative person and quickly told all she knew"- W.M.Thackeray
see also
tediously prolonged or tending to speak or write at great length
"editing a prolix manuscript"; "a prolix lecturer telling you more than you want to know"