But on some wallets (like Electrum), you will be able to spend the coin, but the parent transaction will first get confirmed or be included in the same block the child transaction would be included so that both are confirmed at once.
If I am not wrong the feature is only available on Electrum Android not on PC.
The setting can be found click clicking the green icon top right corner=> preference => Wallet behaviour => 'enable' Spend unconfirmed
OP, you can also try CPFP if the TX fee used for the transaction is low and you want your transaction to be spend immediately.
You are the one that got the correct answer to the OP question.
@Hasslong
Follow Findingnemo guide to enable 'spend confirmed'. It is enabled by default, but you disabled it, which you might not know until now.
Know that if the parent transaction is not confirmed, your transaction (child transaction) will not be confirmed unless you use higher fee that is enough to get both child and parent transactions confirmed.