>> Use regular powder detergent if she is using the new HE or 2x stuff.
The usual problem here is because some people buy the new super concentrated stuff even though they don’t need it. Then they use a lot and get the odor problem. The regular powder will be a lot cheaper too.
>> If it is a sewer stench then the P-trap to the sewer may have dried out. Pour a quart of water down all the drains in the house. The air in the sewer line can vent odors out when the washer empties water into the drain.
>> If the odor is mildew smell, run a full load of hottest water using the Super Shock formula at least twice, double the quantities, set the machine to the smallest load. (no TechnoFresh, laundry or rags required)
>> If the odor is mildew and the Super Shock did not help (or it returns quickly) and she has well water or hard water there is probably a hardness buildup in the drum.
The hardness buildup is porous and the nasties may be down in the nooks and crannies.
Use something like CLR to remove the buildup (Cheapest kind you can find). Pour it into the empty drum. If it foams up, then you have a buildup and it is working to remove it. Add a bucket of water if it is really foaming. Keep adding CLR until it no longer foams.
Run a rinse load to flush out the CLR like stuff.
>> All of these are known solutions to some of the problems people have sent me. Good Luck!