Hopefully ... someone will answer this forum post. It seems that responses to this forum is sparse to say the least.

I have a gMail account. On the iPad, this email account is shown separate from the iPad email (which includes Inbox, Sent Mail, etc.).

How do I set up the feature with gMail on the iPad that will show "sent mail". It is inconvenient not knowing who I sent emails to. I do tap on the "Sent email" icon, but nothing shows up. How do I set that up ?

I have gmail too and I just checked to see if my sent email showed up on the iPad and it didn't. So I sent myself an email to see if it would show and yes, all my sent mail now shows up. Strange, huh?

Welcome
Frankly considering the number of members we have we do provide reasonable job providing support for those whom need it

In respect to your problem I use apple mail on the ipad /iPhone and Macbook which is linked to my gmail account. In apple preferences you can tell mail to send cc yourself. This allows me to have a copy if anything sent on my Macbook iPhone and ipad available on all devices
This may not be what you want to do but it works for me.
There may be an easier way to handle sent mail but at this time considering I have maybe 6 emails a day at most to respond to it is fine.