Create Custom callback for Jet Posts Widgets that crops the transferred text to the specified number of words.

jet-elements-add-custom-meta-callback.php

<?php
        add_filter( 'jet-elements/posts/meta_callbacks', '__your_prefix_add_meta_callback' );

        function __your_prefix_add_meta_callback( $callbacks ) {
                $callbacks['__your_prefix_get_post_words_trim'] = esc_html__( 'Words Trim', 'jet-elements' );

                return $callbacks;
        }

        function __your_prefix_get_post_words_trim( $content ) {
                $trimmed_content = wp_trim_words( $content, 40, '<a href="'. get_permalink() .'"> ...Read More</a>' );

                return $trimmed_content;
        }