Family events

There are some royal events and ceremonies that Countess of Wessex usually attends, on most times with her family. Viscount James, as he’s the youngest member of Wessex family, isn’t seen at most occassions, however there are few events he attended already as well. And there will be more in the future. As of 2016 Viscount James is attending all royal events with his family.
March – April (depending on year)
Traditional Easter Sunday service at Windsor Castle. 
We always see The Countess with Prince Edward & Lady Louise. Since 2016 also Viscount Severn.
May
RHS Chelsea Flower Show
Formally known as the Great Spring Show, is a garden show held for five days in May by the Royal Horticultural Society (RHS) in the grounds of the Royal Hospital Chelsea in Chelsea, London. It is the most famous flower show in the United Kingdom, attracting visitors from all continents.
The Queen, as Patron of the Royal Horticultural Society & other members of Royal Family (including Countess of Wessex) regularly attends the opening of the show, which begins with Press Day on the Monday followed by two private views for RHS members.
Pic by NFU Pics, Chelsea 2011

May – June

The Royal Windsor Horse show
Annual fixture for which the Royal Family have a great affection.
Held annually for five days in May or June in Windsor Home Park, the Royal Windsor Horse Show has always enjoyed the enthusiastic support of the Royal Family. The Queen became Patron in 1952, and two years later she donated The Queen’s Cup for Armed Services team jumping.
For the last few years attended by the whole Wessex family.
June
Royal Ascot
The centrepiece of Ascot’s year, Royal Ascot is one of Europe’s most famous race meetings, and dates back to 1711 when it was founded by Queen Anne. Every year Royal Ascot is attended by HM Elizabeth II and various members of the British Royal Family.
The Royal Meeting, held in June, remains a major draw, the highlight being the Gold Cup. The most prestigious race is the King George VI and Queen Elizabeth Stakes run over the course in July.
We always see The Earl & Countess of Wessex.
For the last few years, during Christmas Ascot meeting in December, we saw the whole family together.
June
Trooping the colour
The Sovereign’s birthday is officially celebrated by the ceremony of Trooping the Colour on a Saturday in June.
The tradition of Trooping the Colour:
Although The Queen was born on 21 April, it has long been the tradition to celebrate the Sovereign’s birthday publicly on a day in the summer, when good weather is more likely.
Trooping the Colour is carried out by fully trained and operational troops from the Household Division (Foot Guards and Household Cavalry) on Horse Guards Parade in Whitehall, watched by members of the Royal Family, invited guests and members of the public.
http://www.flickr.com/photos/mikepaws/9051423080/sizes/l/
Picture by Mikepaws used under a Creative Commons license, June 2013
You can see The Wessex family along with other members of Royal Family.
June
Garter Service
Each year in June a procession and service take place at Windsor Castle for the Order of the Garter.
The Order is the senior and oldest British Order of Chivalry, founded by Edward III in 1348.
New appointments to the Order of the Garter are usually announced on St. George’s Day (23 April) but the chivalric and installation ceremonies take place in June, on the Monday of Royal Ascot week, known as Garter Day.
The Queen attends the service along with other members of the Royal Family in the Order, including The Duke of Edinburgh, The Prince of Wales, Prince William, The Duke of York, The Earl of Wessex, The Princess Royal, The Duke of Gloucester, The Duke of Kent and Princess Alexandra.
The Garter ceremonial dates from 1948, when formal installation was revived by King George VI for the first time since 1805.
http://www.flickr.com/photos/nick777/4701262844/sizes/l/
Pic by Nick Warner, Grater Procession 2010
November
Remembrance Day
The Remembrance Day ceremony is held on the second Sunday in November at the Cenotaph in Whitehall, London. Each year, the ceremony is attended by The Queen and other members of the Royal Family in addition to other Remembrance events held in the same week, notably the opening of the Field of Remembrance at Westminster Abbey and the Royal Festival of Remembrance at the Royal Albert Hall.
It is always attended by The Earl & Countess of Wessex.
December
Queen’s annual pre-Christmas lunch at Buckingham Palace
We only see pictures of members of Royal Family arriving & departing from Buckingham Palace.
Traditional Christmas service at Sandringham
Each year we see pictures of members of Royal Family attending Christmas Church Service at Sandringham Estate. Wellwishers gather along path leading to the church, greeting members of Royal Family either arriving or departing from the church.

You can read more about Royal Events & Ceremonies at The Official Website of The British Royal Family. Click here.

http://www.flickr.com/photos/bdubsphotos/11548190534/sizes/l/picture by brandon_williams618
December 2013, The Earl & Countess of Wessex with Lady Louise.