DOE Bronze this weekend - rucksack size help

[Solent123]

Help please - DD is doing her DOE bronze this weekend and I have just realised that her sleeping bag takes up just about all the room in her 50L backpack, if I squash it down then we might be able to squeeze some skins and a spare fleece on top and possibly wipes and a toothbrush but then there's no room for a toilet roll or any food, should I do an urgent Amazon prime order tonight for a 60L rucksack? DD is barely 5ft tall so I'm worried that a large adult rucksack won't adjust properly for her but I think she'd rather go without a sleeping bag than not take marshmallows 😂

Have you got a go outdoors nearby?
DD has used this for years. Fits everything for DofE. Sleeping bag in the bottom section.
https://www.gooutdoors.co.uk/15989081/eurohike-nepal-65-rucksack-15989081

Also use a compression sack for the sleeping bag. There are several sizes and will properly squish the sleeping bag
https://www.gooutdoors.co.uk/15984128/oex-compression-sac-10-15984128

Thank you, I do have a Go Outdoors nearby - that ruck sack looks like a bargain but there a couple of reviews saying its not great on backs, I suppose that could be down to adjusting it though and not putting too much weight in there to start with - I also had no idea that you can get Compression sacks, its hard enough squeezing it into the bag it came with.

So bigger is better then.

Can you tie the sleeping bag on the outside?

@Solent123 honestly it's fine. We've got 3 and back packed lots. They've been used on 3 D of E expeditions.
Make sure the waist straps and snug on the hips so all the weight is taken there. Then adjust shoulder straps.

...and does the original sleeping bag bag have straps to squish, or is it just a draw string bag?

If the latter, then definitely get the compression sack and don't use the original.
I'd take the sleeping bag with me so the staff can decide the size needed 🙂

Agree: compression sack for sleeping bag. To stuff it into bag, don't roll up and try and put it in one go, just stuff in one end and then just keep pushing it in until you can close the drawstring.
https://m.youtube.com/watch?v=WMYmJgGRGWg

Not really, the groundmat is going on the outside underneath - the straps wouldn't fit around the sleeping bag.

@House4DS I've just ordered the one you recommended, I can return the 50L one - thank you!