Filesize is determined by duration x bitrate
Cannot change the length so raise the bitrate quite a bit.
What format was the original clip (might be a whole different codec).
If your sequence settings are the same as your source clip, then check the box for Match Sequence Settings on the Export Settings panel.
What format are you picking for export?
If they are going to edit the clip, you may want to pick a lossless intermediate format. I don't know what is currently being used for that.
If you have a compressed clip already, Andrea export to a compressed format, may have a generation loss.
format I have to export is H264.
the original clip is .mov
I will change the export to .mov and see the results. Increasing the bitrate did not change much.