Based on the ephemerides published by JPL Horizons for Marco-A and Marco-B,
a visualization of the orbit of Marco-A before and after the recent fly-by (during which both CubeSats relayed the telemetry data from NASAs InSight landing):
This graph was created using the great poliastro library (by @astrojuanlu).
Source code: see the my jupyter notebook (here you can also find graphs showing the development of the orbital parameters during the fly-by)