Artsonline has dated this piece to the 17th Century.
Brief Description:

Circa 1670-1710
As one can see from these images, the sitters have adorable facial expressions with excellent attention to detail to their period, religious clothing.
The work is currently mounted (unframed).

It displays well without a frame; however, I believe the piece is deserving of an impressive/quality period frame to show it off to its full potential.
Indeed, it is a fascinating oil that has the all-important Old Master charm.

Attributes:
Oil on relined canvas
Polish School
Circa: late 17th/early 18th-century
Condition:
The painting presents beautifully, having undergone a full and professional restoration sometime during the 20th-century.

Framed Measurements:
INCHES & CENTIMETRES
Height: 24.6'' | 62.4 cm
Width: 20.4'' | 51.8 cm
Depth: 0.9'' | 2.2 cm
^^ Fast & Free UK Delivery Included^^
A Certificate Of Authenticity (COA) will be provided by artsonline with this piece*

Delivery
Artsonline UK ships worldwide daily, using only fully insured, priority, and fully tracked delivery services.
Great care and much time are taken over the safe transportation of the Fine Art and Antique pieces that we sell.

We pack extremely carefully, so you can rest assured that your piece will arrive with you in perfect condition.
For larger paintings, antique furniture pieces, and fragile items that can not be sent via the normal postal services, we use professional door-to-door delivery providers, who will always strive to deliver your piece promptly, within approx. 7-14 working days.

Returns Policy
Artsonline provides a genuine no-quibble 14-day money-back refund policy
(excluding the cost of Postage and Packaging).
Pay Securely - Telephone orders are welcome
Image result for payments accepted logos
Secure-Payment-VPADeb-sa-la-go-th-et-an-gt-0012086-BACS-Order-PayPal-M/Card
Artsonline has dated this piece to the 17th Century.
Specialising in fine art & quality pottery - worldwide delivery - secure payments
You can view the stock and full dealer information on the Artsonline Profile Page