Please set your display name to what you prefer instead of what Google chooses for you. Here's how to do it:
1. Click on the profile button with the gear:
2. Click on "Membership and email settings"
3. Select whether you want to "Link to my Google profile" if you have one and/or edit your display name:

I think it's best to display your real name, since there should be no need to use an alias or be anonymous in a genealogy group.
4. You can also set your email delivery preference here.
5. Click the Save button.
That's it!