The tenant should make note of any time the landlord enters their unit without notice. The tenant may want to write to the landlord and remind the landlord of their obligation to provide notice of entry. If there is a dispute in the future, the tenant will have proof that the landlord was advised of the issue.
It is an offence under the Residential Tenancies Act for the landlord to fail to provide the proper Notice of Entry. The tenant may want to call Service Alberta to find out about filing a complaint against the landlord.