Bringing my personal Jewellery

Me and wife arrived to UK in 2010, since then we were only been able to visit back India only once. Most of her personal jewelry still sits in bank locker in India.
Now we are due to visit India and want to bring back jewelry with us.
I don't know it's worth and we don't want any hassles at the airport.

What is the best way to bring it to the UK?
Shall I bring small amount and pass through green channel? How much is the green channel allowed amount?
Shall I bring all of it and declare in UK?
What if the baggage gets lost in transit?

See also Bringing goods into the UK for personal use

Allowance for other goods
You can bring in other goods worth up to £390 (or up to £270 if you arrive by private plane or boat).

If you go over your allowance you pay tax and duty on the total value of the goods, not just the value above the allowance.

You may have to pay import VAT and customs duty if you exceed your allowance.

Keep valuables in hand-luggage or wear on person.

Since we're traveling as a family of 4. Two kids and two adults, so would the amount be 2x£390?
Any allowance for kids?