Leaking diapers at night

My daughter is 7 weeks and uses Huggies Special Delivery diapers for day and night. They usually work great, but lately I’ve been noticing a wet spot on her back right above the diaper line when I change her for her first feeding at 6am after sleeping for 7 hours, so I think she’s leaking out the back. We just moved her into size 1 diapers, but do you think I need to go up a size at night? The Velcro latches overlap when I secure them around her waist, so they’re plenty big on her in general. Should I switch diaper brands? Or maybe put an insert at night? Any suggestions. Thanks!