Hi Fairymoss,
I think you could use a 25-30 litre backpack or one that is built for shorter torso (e.g. kids or teens) as you are quite petite. For your hubby, he can try a 35-litre hiking backpack or a travel pack. Check this out:
BUGEurope.com >Guide to packing
Bring less, wash more!
Brands of backpacks - Mine was a Deuter TransAlpine 90, a hiking/biking backpack. Loads from the top. My hubby's bag is a Tatonka travel pack (front loading) with zip-off daypack, which I think is no longer produced. I actually prefer the travel pack but could not find one in 35 litres.
Search the internet for tips on packing light.
Rick Steve's Graffiti Wall
Tips for Packing Light and traveling with just carry on luggage
Backpack weight:
To test yourself, fill up a backpack to abt 7-8 kg, carry it and go shopping for a few hours, and see how it feels. (Of cos, the better designed the bag, the more comfortable it will feel.) This should be the max weight of what you are bringing. For your hubby, try 10 kg max. Try to go even lighter if possible (yes it is!)
What to pack - basically, wear the bulkier or at least the heavier items, then pack the rest. E.g. if bringing hiking boots, wear them and stow your sandals inside the bag. Wear the heavy jeans and pack the dress pants, etc.
You can bring very basic makeup - one lipstick and eyeliner (double as eyebrow pencil), eyecolor, maybe some concealer. This will hardly take up any space and also v light. Forgo the foundation and brushes and other heavy stuff, because then you'd have to bring makeup remover extra cotton, etc - so bothersome!
As for cosmetics, I think it's fine to bring, just use the small bottles that you can get fr the $1 stores or Watsons, not the original big bottles. Restrict yourself to 3 items: cleanser, toner and moisturizer, leave the rest at home. Share combination bathgel/shampoo (Body Shop) with your hubby. Buy travel toothpaste, or use a almost-finished tube. Anything that is liquid is heavy!
Contact lens - I brought daily disposables but ended up wearing it on one day only. Was too exhausted and in a big hurry most days to care about putting them on!! If you want to look good in photos, just take off your specs and pretend.
What I brought to Europe (2 weeks in spring):
5 tops, 1 sweater, 1 jacket
1 Blue jeans, 1 Black slacks
1 Black ankle-high leather boots
1 pair insoles, 7 pairs socks
2 silk scarves, some inexpensive accessories
Guide books, maps, notes
tickets, passport, credit cards, cash
Plastic ziplocs, Inflatable clothes hangers
money belt (MUST use at all times!)
small day pack, Waterbottle, Combination locks
water heating coil (used for cooking cheap meals)
Lightweight heatproof plastic jug(!!!)
You may need to modify the list for summer clothing!