I am so pleased you have your mum with you and will have a necklace on the way Jade. Your mum will be very proud of your determination and bravery you are a great honour to her.
For people commenting about basic this and cheaper that, people leave this earth just the once and when it's someone you love you want that to be seen and felt. If that means hundreds of pounds worth of flowers and travelling in the expected car you will do it. Remember when in the midst of grief it is hard to see clearly and you are lead by the people who deal with it daily.
Fwiw when we buried my stillborn we didnt have flowers as we had just spent hundreds on mils and putting a notice in the paper. It didnt seem worth it. We didnt invite friends or have a wake. we should have.