How do I mirror entire sketches onto a work plane?

Heya!

I've got this little problem here; I'm trying to mirror these sketches onto a work plane, but I can't seem to find the right operative.

Basically I'm trying to do the same thing, that the 3D mirroring tool does; but -of course- it only mirrors features and not sketches. I tried searching round' and found nothing!

Any help would be appreciated!

https://preview.redd.it/ry27aewehbbf1.png?width=1920&format=png&auto=webp&s=fbdf5800e89df74e4e35e2fb9db04d49d39b64d6

https://preview.redd.it/7gqg0jofhbbf1.png?width=1920&format=png&auto=webp&s=2334fba6da96c9bd6a7b1ef8e24f095aa81abfac

https://preview.redd.it/1olwgogghbbf1.png?width=1920&format=png&auto=webp&s=6bf0da834101f7bcb2fd60763fb469601a428b72