Template Default Question

defaults to a page rather than to her blog,

Check if the theme to that original site has a home.php OR if in its Admin > Settings > Reading, “Front Page Displays” > A Static Page with a specific page for the home page. To get it back to blog form, just reset the Reading Panel to “Front Page Displays” > Your latest posts.

I added a home.php template to the theme. I have created a “home” page in the pages section, but the two do not link together.

They won’t link together. You should check out codex re Template Hierarchy wherein:
If a visitor goes to your home page at https://example.com/, WordPress first determines whether it has a static front page. If a static front page has been set, then WordPress loads that page according to the page template hierarchy. If a static front page has not been set, then WordPress looks for a template file called home.php and uses it to generate the requested page. If home.php is missing, WordPress looks for a file called index.php in the active theme's directory, and uses that template to generate the page.
Therefore if you want to create a special template page for a home page using Pages, do not name it home.php. If you want to set up and upload home.php, do not create a static front page named Home. Use one or the other method.

Well that stinks!

So I’ll probably have to leave everything in the home.php file. Which will make it harder for my friend to edit herself.

If I knew the file path to the pages files, could I do an include or require in php? Probably not, WordPress would probably try to create duplicate pages one using home.php and another using index.php.

So now I need to find out how to edit the php in the sidebar to including a link back to the “home” page now that it will no longer be in the “pages” section WordPress won’t automatically generate one.

Can any one help me there?

What I posted above was that you have to use one or the other method. So you have option of either
1) a home.php which will automatically be the home page OR
2) us a Page set as Home page in Setting > Reading > Front Page is …
And that Page can either be:
a. a regular Page or theme’s page.php OR
b. Page template created (you can call from Page > Add New > Attributes box) named page-home.php

I understand that. But I’m going to need a link back to my home page now that WordPress won’t automatically create one. My PHP reads as follows:

<ul>
<?php

// for sidebar widgets
if ( !function_exists( 'dynamic_sidebar' ) || !dynamic_sidebar( ) )
{

    // search bar
    sp_sidebar_open( "searchbar", "<h2>Search</h2>" );
    include (TEMPLATEPATH . '/searchform.php');
    sp_sidebar_close( );

    // pages
    sp_sidebar_open( "pages", "<h2>Pages</h2>" );
        echo '<ul>';
        wp_list_pages("title_li=&sort_column=menu_order&class=");
        echo '</ul>';
    sp_sidebar_close( );
} // sidebar widgets

?>
</ul>

I’ve tried the following code to add a real home link in but it just causes all the image links of the page to flicker when the mouse is over them and doesn’t add the link I want.

<ul>
<?php

// for sidebar widgets
if ( !function_exists( 'dynamic_sidebar' ) || !dynamic_sidebar( ) )
{

    // search bar
    sp_sidebar_open( "searchbar", "<h2>Search</h2>" );
    include (TEMPLATEPATH . '/searchform.php');
    sp_sidebar_close( );

    // pages
    sp_sidebar_open( "pages", "<h2>Pages</h2> <ul><a href=\"https://www.elizabethhanbury.com\">Home</a></ul>\n" );
        echo '<ul>';
        wp_list_pages("title_li=&sort_column=menu_order&class=");
        echo '</ul>';
    sp_sidebar_close( );
} // sidebar widgets

?>
</ul>

See:
https://sheynawatkins.com/wordpress/