One solid evidence would be: showing Wallet A's master public key. But that involves showing all of your wallet's addresses and transactions.

By giving it to someone who knows Bitcoin, it will be possible to show that the change (UTXO) from that particular transaction was the one sent to WalletB because they were derived from the same SEED.
If the wallet isn't HD (Hierarchical Deterministic) or the used change address was just imported, this can't be used because anyone can just "import private key" to add the address to the wallet.

Providing the transaction ID alone isn't that solid IMO, it's too easy "fake" the change address by using "coin control" or "pay to many" option/command.

the only sure way that you can prove ownership of an address is by having the private key of that particular address and signing a message.

just receiving some coins from that address is not proof of ownership. so even if you show that address A has sent you 175BTC or even more transaction at other times, is not proving that address A belonged to you so you can't prove the transactions going out of that address were sent by you.
that would be like if someone sent you money via wire transfer and then you go to court trying to prove you own that other bank account just because it sent you money!