How do I connect to my Mother's side on the pedigree chart

You will need to create 'placeholder' persons for any living persons (your mother or her parents for example) then connecting them to your deceased relations on your mother's lines will make her Tree visible to you.

So you just have to 'fill-in the gap' between living persons and connect them to the appropriate lines that are likely already in the Tree.

There is probably a Help Center document that can be referred to but that is the basics of the process.

I hope this helps.