My 8 year old daughter had an extremeky large cavity in her top back molar. She was missing 4 sides of the tooth. They recommend a root canal but there really isn't any tooth left to save. Would u still recommend a root canal or get it pulled and use a sp

Dental Treatment. Root canal therapy is only part of the picture... if the tooth is missing much of it's structure, then a crown would also be necessary. Much to discuss with an endodontist and the restorative dentist.
Try to Save It. Even if the tooth does not appear to have much structure left to support a restoration, its retention is important to preserve the supporting bone. A root canal and a restoration may be a long-term temporary solution until something more definitive can be done at a later date, such as an implant.
Get help. if its top back tooth in an 8y old it's a 6y molar, a permanent tooth. Unlike baby teeth if a permanent tooth is lost there is no additional permanent tooth waiting to replace it. Please consult with Orthodontist and with Endodontist (Root Canal Specialist). Removal of permanent molar has serious Orthodontic consequences. What you do now will affect the rest of her life. Seek consultations.
Visit a pedodontist. If the tooth can be saved with root canal, the pedodontist will discuss your options for stainless steel crown.