Using bitcoin-qt. Address with my funds does not show up. Can I import it?
You're probably safe. If you were using an old version of Bitcoin Core, it used to keep a key pool of 100 unused addresses around. When you request a new receiving address, one from that pool gets used. So, unless you received numerous transactions between the backup and the last transaction, your last transaction should be covered by the backup containing these 100 unused addresses.

If you're using a new version of Bitcoin Core, its wallet uses a hierarchical determistic key derivation where a single backup will always be enough to regenerate any later generated addresses.

Therefore, you should see our transactions appear when your Bitcoin wallet has synchronized with the current state of the network.