Tracy Beaker is back, along with her weedy friend Peter and arch-enemy Justine Littlewood. They are looked after by Mike and Jenny who work at the children's home where they all live.
It's Valentine's Day in the children's home, or the Dumping Ground as Tracy calls it. Peter's feeling all fuzzy and generous and decides he wants Tracy to be his Valentine. He gives her his nan's treasured gold locket to prove it!
Tracy reckons it must be worth a fortune and she hatches a plot to sell it for loads of money, or maybe even swap it for something way more cool.
But will it work? And should she really give away something that's been in Peter's family for ages?
CBBC's Barney makes a special appearance. The drawings in the book really look like him!
There's a brilliant bit about gunge. One character ends up in the sticky, gooey green stuff. But who could it be?
The book is great fun and and easy to understand.
The only downside is it is much shorter than other Jacqueline Wilson novels so you might think it ends too quickly - but because it's shorter, it's cheaper too!
The book is on sale to raise money for Comic Relief.
This reviews page is now closed. Here are some of the reviews you sent in.
"I think Tracy Beaker's Thumping Heart is very good and I think it is a good idea to make it Valentine's Day in the book."
Tia, 10, Cheshire, England
"Tracy Beaker's Thumping Heart is a fantastic book and overall the best thing is that all the money is going to charity."
Amy, 10, Northamptonshire, England
"I read this book in a few hours because I could not put it down! I really enjoyed it!!"
Evie, 12, Leeds, England
"I think this is one of Jacqueline Wilson's best books, it is very enjoyable."
Lauren, 12, Glasgow, Scotland
"I enjoyed this book quite a lot, but I think it was a bit short and the others are a bit better."
Ella, 11, Surrey, England
"It's a fantastic book with a great storyline."
Henna, 12, Halifax, England
"I loved the book, it's great and I love Tracy Beaker and I think she's a bit like me."
Zoe, 9, England
"I think this is a great book and very funny. It's not really about Red Nose Day though, it's all about Valentine's Day, but overall I would give it 5/5."
Hannah, 11, Cheshire, England
"This book is so good and very funny. It has Basil's Swap Shop in it too. It was so good I read it in an hour."
Becca, 10, Cornwall, England
"Tracey Beaker's Thumping Heart is probably the best book I have ever read."
Samuel, 9, Oxford, England
"I think the book is very humorous and very cute, it's also very emotional. Jacqueline Wilson is my favourite author."
Chloe, 11, Sunderland, England
"This book is wicked and funny."
Mollie-Mae, 9, Leicester, England
"I think this is a great book! And it's so funny too. Everyone who likes a good read should buy it and have a good old laugh."
Tish, 12, Hampshire, England
"This book - WOW! I love to read and I'm not just saying this but it is one of the best books ever!"
Erin, 11, Scotland
"Fabulous novel by Jacqueline Wilson - once again!
Stephanie, 12, Essex, England
"Tracy does it again! One of the best books ever!!"
Eimear, 9, Ireland
"This book was very humorous and enjoyable. I absolutely adore Tracy and the crew! It is one of the best books yet!"
Yasmin, 11, Shropshire, England
"Tracy Beaker is the best character of all Jacqueline Wilson's characters. This is the best book of all her books."
Nicole, 11, Glasgow, Scotland
"Tracy Beaker's Thumping Heart is a great book overall. And the best thing is that the money will be going to charity!"
Shannon, 11, Hertfordshire, England
"I personally don't like this one because all her books are basically the same. Also, she reveals the endings to other great books in her stories."
Kilda, 13, Brussels, Belgium
"I thought this book was absolutely amazing and I can't wait for the next one!"
Chloe, 11, UK
"I love Tracy Beaker and this has to be one of the best books yet!!!"
Lucy, 10, Monmouthshire, Wales
"I like Tracy Beaker because it is very funny and adventurous, my mum even enjoys it."
Hajra, 11, Lancashire, England
"I thought the book was fantastic and I'd give it 10 out of 10!"
Layla, 11, Derby, England
"I thought the book was easy to read and to understand - it was very funny. I love Tracy Beaker."
Caitlin, 9, UK
"I really enjoyed it. It made me laugh so much, but I wish it was longer and the ending was surprising."
Julie, 12, Birmingham, England
"I loved every minute of this book! Although I wish it was longer. My favourite bit is at the end!"
Holly, 11, England
"It is a really funny book and if you like Tracy Beaker, then you will like this!"
Sarah, 11, Lancashire, England
"It was quite good but it was not the best book I have read!!
Annalise, 8, Dorset, England
"This is the best book ever! It's brilliant and Tracy is an ace character. Jacqueline Wilson is phenomenal!"
Rebecca, 12, Highlands, Scotland
"I have to admit it wasn't her best book, but I still enjoyed it."
Katie, 13, Wiltshire, England
"It was really good! I stayed up reading it all night!"
Aisha, 12, Birmingham, England
"It was so good and I'm Jacqueline Wilson's biggest fan ever!!"
Alicia, 10, Somerset, England
"This book is absolutely fab. I would recommend it for seven to 11-year-olds. It's great!!!"
Kehinde, 9, Oxfordshire, England
"The book was fantastic! It was the best book I've ever read."
Phoebe, 10, Wolverhampton, England