If a person is on H4 EAD, can he/She work for 2positions one is full time(permanent) with client and other is on W2(contract position)
Yes, in fact you can work as many jobs as you want on H4 EAD. You can also own a business.
My wife ia doing 2 jobs on h4 ead . Will there be any issues dueing visa stamping ? In ds 160 she can only fill one current employer . How should she handle this
No issues, she can work as many jobs as she can handle. H4 EAD has no restrictions for job/role/number of concurrent employers.
This is fine, just enter one of the employer.