您需要修改2个函数，而不仅仅是functions.php:

/**
 * Function to display footer content.
 *
 * @since 1.1.24
 * @access public
 */
//ADDED CHILD TO THE END OF THE NAME
function hestia_the_footer_content_child() {
    /**
     * Array holding all registered footer widgets areas
     */
    $hestia_footer_widgets_ids = array( \'footer-one-widgets\', \'footer-two-widgets\', \'footer-three-widgets\' );
    $hestia_footer_class = \'col-md-4\';
    $footer_has_widgets = false;
    $hestia_nr_footer_widgets = get_theme_mod( \'hestia_nr_footer_widgets\',\'3\' );

    /**
     *  Enabling alternative footer style
     */
    $footer_style = \'\';
    $footer_style = get_theme_mod( \'hestia_alternative_footer_style\', 0 );
    if ( isset( $footer_style ) && $footer_style == 0 ) {
        $footer_style = \'footer-black\';
    } else {
        $footer_style = \'\';
    }

    /**
     *  Get the widgets areas ids and class corresponding to the number selected by the user
     */
    if ( ! empty( $hestia_nr_footer_widgets ) ) {
        $hestia_footer_widgets_ids = array_slice( $hestia_footer_widgets_ids, 0, $hestia_nr_footer_widgets );
        switch ( $hestia_nr_footer_widgets ) {
            case 1:
                $hestia_footer_class = \'col-md-12\';
                break;
            case 2:
                $hestia_footer_class = \'col-md-6\';
                break;
            case 3:
                $hestia_footer_class = \'col-md-4\';
                break;
            case 4:
                $hestia_footer_class = \'col-md-3\';
                break;
        }
    }
    /**
     * Check if the selected footer widgets areas are not empty
     */
    if ( ! empty( $hestia_footer_widgets_ids ) ) {
        foreach ( $hestia_footer_widgets_ids as $hestia_footer_widget_item ) {
            $footer_has_widgets = is_active_sidebar( $hestia_footer_widget_item );
            if ( $footer_has_widgets ) {
                break;
            }
        }
    }

    hestia_before_footer_trigger();
    ?>
    <footer class="footer <?php echo esc_attr( $footer_style ); ?> footer-big">
        <?php hestia_before_footer_content_trigger(); ?>
        <div class="container">
            <?php
            if ( $footer_has_widgets ) {
            ?>
                <div class="content">
                    <div class="row">
                        <?php
                        if ( ! empty( $hestia_footer_widgets_ids ) ) {
                            foreach ( $hestia_footer_widgets_ids as $hestia_footer_widget_item ) {
                                if ( is_active_sidebar( $hestia_footer_widget_item ) ) {
                                    echo \'<div class="\' . $hestia_footer_class . \'">\';
                                        dynamic_sidebar( $hestia_footer_widget_item );
                                    echo \'</div>\';
                                }
                            }
                        }
                        ?>
                    </div>
                </div>
                <hr/>
                <?php
            }
            ?>
            <?php hestia_before_footer_widgets_trigger(); ?>
            <div class="hestia-bottom-footer-content">
                <?php
//ADDED CHILD THIS IS THE CALL TO THE COPYRIGHT
                hesta_bottom_footer_content_child();
                ?>
            </div>
            <?php hestia_after_footer_widgets_trigger(); ?>
        </div>
        <?php hestia_after_footer_content_trigger(); ?>
    </footer>
    <?php
    hestia_after_footer_trigger();
}
//WE CHANGE THE ACTION NAME AND THE CALL IS TO OUR FUNCTION NOW
add_action( \'hestia_do_footer_child\', \'hestia_the_footer_content_child\' );

    //THIS IS YOUR MODIFIED FUNCTION
    function hesta_bottom_footer_content_child( $is_callback = false ) {
    if ( ! $is_callback ) {
    ?>
        <div class="hestia-bottom-footer-content">
        <?php
    }
    $hestia_general_credits     = get_theme_mod(
        \'hestia_general_credits\',
        sprintf(
            /* translators: %1$s is Theme Name, %2$s is WordPress */
            esc_html__( \'Designed by HCL Design\' ),
            sprintf(
                /* translators: %s is Theme name */
                \'<a href="https://themeisle.com/themes/hestia/" target="_blank" rel="nofollow">%s</a>\',
                esc_html__( \'Hestia\', \'hestia\' )
            ),
            /* translators: %s is WordPress */
            sprintf(
                \'<a href="%1$s" rel="nofollow">%2$s</a>\',
                esc_url( __( \'http://wordpress.org\', \'hestia\' ) ),
                esc_html__( \'WordPress\', \'hestia\' )
            )
        )
    );
    $hestia_copyright_alignment = get_theme_mod( \'hestia_copyright_alignment\', \'right\' );
    $menu_class                 = \'pull-left\';
    $copyright_class            = \'pull-right\';
    switch ( $hestia_copyright_alignment ) {
        case \'left\':
            $menu_class      = \'pull-right\';
            $copyright_class = \'pull-left\';
            break;
        case \'center\':
            $menu_class      = \'hestia-center\';
            $copyright_class = \'hestia-center\';
    }
    wp_nav_menu(
        array(
            \'theme_location\' => \'footer\',
            \'depth\'          => 1,
            \'container\'      => \'ul\',
            \'menu_class\'     => \'footer-menu \' . esc_attr( $menu_class ),
        )
    );
        ?>
    <?php if ( ! empty( $hestia_general_credits ) || is_customize_preview() ) : ?>
        <div class="copyright <?php echo esc_attr( $copyright_class ); ?>">
            <?php echo wp_kses_post( $hestia_general_credits ); ?>
        </div>
    <?php endif; ?>
    <?php
    if ( ! $is_callback ) {
    ?>
        </div>
        <?php
    }
}

<?php do_action( \'hestia_do_footer_child\' ); ?>