Historically, when the tax year started, there are a bajillion topics for how to find out what they got. And for due diligence, you can help them or try it yourself. For instance, there is a web portal, for them to set up an online account to access their IRS account, which will show this info as part of the transcript.

I even have these macros...

Stimulus info can be found at these links:

https://www.irs.gov/payments/view-your-tax-account

https://www.irs.gov/coronavirus/economic-impact-payment-information-center

https://www.irs.gov/coronavirus/get-my-payment

https://www.irs.gov/coronavirus/second-eip-faqs

https://turbotax.intuit.com/stimulus-check/

https://ttlc.intuit.com/community/articles/community-news-announcements/second-stimulus-resources/05...

And: "The IRS said you can check the status of your second stimulus payment at IRS.gov/GetMyPayment (GMP).

If GMP reflects a direct deposit date and partial account information, then your payment is deposited there. If the payment was mailed, it may take up to three or four weeks to receive the payment. Watch your mail carefully and be sure not to throw out your payment.

If GMP shows “Payment Status #2 – Not Available,” then you will not receive a second stimulus check and instead you need to claim the Recovery Rebate Credit on your 2020 Tax Return."

Here's a link to the image for seeing the payment(s) as an account transcript image example, which you can get for them or they can get for themselves:

https://www.irsmind.com/irs-notices/irs-transcripts-now-provide-stimulus-payment-information/

Good luck.

And:

https://www.irs.gov/newsroom/economic-impact-payment-information-center-topic-a-eip-eligibility

https://www.irs.gov/coronavirus/second-eip-faqs#Eligibility

https://www.irs.gov/newsroom/irs-is-issuing-third-round-of-economic-impact-payments
https://www.irs.gov/coronavirus/third-economic-impact-payment
https://www.irs.gov/newsroom/more-economic-impact-payments-set-for-disbursement-in-coming-days-taxpa...
https://www.irs.gov/newsroom/more-details-about-the-third-round-of-economic-impact-payments


One for each of the three EIP “stimulus” payments.

And of course, ask them to bring their bank statements to you. A majority were paid by direct deposit; then, checks means they might have deposited them.