How sad! That you have absolutely no nice things to say about your mum. I am just wondering why you feel the need to say anything? Is it for your brother abroad? Often the minister or whoever is there will talk on behalf of relatives. He will keep it low and be guided by what you tell him. It is not compulsory to do an eulogy.
If you feel you do need to say something then perhaps a thoughtful poem like the ship by Bishop Brent?
What is dying
I am standing on the seashore, a ship sails in the morning breeze and starts for the ocean.
She is an object of beauty and I stand watching her till at last she fades on the horizon and someone at my side says: "She is gone."
Gone!
Where
Gone from my sight that is all.
She is just as large in the masts, hull and spars as she was when I saw her, and just as able to bear her load of living freight to its destination.
The diminished size and total loss of sight is in me, not in her, and just at the moment when someone at my side says,
"She is gone"
there are others who are watching her coming, and other voices take up a glad shout:
"There she comes!"
and that is dying.
It must be so hard for you having so few people there. My advice would be to do just what you feel appropriate but don't leave room for regrets.