If I am working can I collect my widow's pension and if so is there a limit I can make?
My answer assumes that you're referring to Social Security widow's benefits, and not disabled widow's benefits. In that case, if you are full retirement age (FRA) or older then the answer is yes. And, there is no limit on how much you can earn once you reach FRA. However, if you're under FRA then your benefits could be subject to full or partial withholding due to the Social Security earnings test (https://www.ssa.gov/planners/retire/whileworking.html).
In years prior to the year you reach FRA you can earn up to the annual exempt amount (i.e. $17040 in 2018) without losing any benefits, but you would lose $1 of benefits for each $2 that you earn in excess of that amount unless you could be paid more using the monthly earnings test (https://www.ssa.gov/planners/retire/rule.html).
In the year you reach FRA you can earn up to a higher amount (i.e. $45360 in 2018) without losing benefits, and only earnings in the months prior to the month you reach FRA count toward the limit. Furthermore, in the year that you reach FRA you would only lose $1 of benefits for each $3 that you earn in excess of the exempt amount.
Our maximization software is fully programmed to handle earnings test considerations, and could likely help you determine your best strategy with regard to when to claim your widow's benefits and/or retirement benefits from your own work record.