You can send your pets on quests in the quests tab, provided
they're the ones the quest givers are looking for.
If the quest needs a female Puma for a mission, you send it
off.
If the quest needs a pet with a Silly disposition, you send it
off.
If the quest needs a white Roc, you send it off.
If the quest needs a dragon with Fearsome Look, you send it
off.
Quests change daily, so keep an eye on the quests board and
fulfill as many of them as you can. It's five quests per day
without the Embassy building on your manor, and six or seven with
an Embassy building.
Other ways you can make silver is buy selling pets on the Pet
Trades. You can also send your pets to the Pound for an easy 500
silver per pet.
You can also find small amounts of Silver coins when exploring,
but the higher the level of your pet you're exploring with, the
more Silver coins and treasure you can find.
Also depending on what level your Town Hall is, you are given a
certain amount of Silver coins per day. The higher your Town Hall
level is, the higher your daily allowance of Silver coins.