Irons
Golfers with slower swings should take the following into consideration when choosing their irons. First of all, you should probably have a 6 or 7 iron as your longest iron club. Only carry a 5 or even a 6 iron if you can hit it confidently and consistently. Most people with slow swings cannot accomplish this. Higher number fairway woods and hybrids will replace the long irons. Another consideration is a wide sole that is rounded to prevent from digging more into the ground and slowing the club face even more. For the same reason don't choose a large iron head design. By all means, do use irons with a deep back cavity and perimeter weighting.
Hybrids
You should use hybrid clubs to replace at least your long irons. The Nancy Lopez ladies golf club line offers sets with hybrids up to the 7 iron in some cases, and even some sets with hybrids completely replacing all the irons except the pitching and sand wedges. Which hybrids you choose will depend on which fairway woods you carry. You will need to determine how far your ball will fly with your highest numbered fairway wood and then choose your lowest numbered hybrid to fly 10-15 yards less than that. The Nancy Lopez site will give you a good idea about what club choices are appropriate for your swing and ability level.
Wedges
Your pitching wedge (PW) should have at least 4 degrees more loft than your 9 iron. The sand wedge (SW) should have at least 56 degrees of loft or even more. There is probably no need for a gap wedge (GW) unless you have a substantial difference in how far you hit the PW compared to the SW. For people with slower swing seeds, this difference is not normally enough to justify another club. A lob wedge (LW) can also be a good addition to your set. For both the SW and the LW, there is no need for golfers with slower swings to have a large bounce angle, since there will not be enough force in the swing to dig too far into the sand or ground in any case.
Conclusion
If you are a serious golfer and can afford it, the best solution for a great set of ladies golf clubs is to find a certified custom fitter and club maker. The standard, off-the-shelf sets of ladies golf clubs sold in most shops will only fit a small percentage of the population. It is essentially a 'one size fits all' proposition. Another good alternative is the Nancy Lopez ladies golf club product lines. You should at least look at their web site to see how they approach fitting your clubs and choosing the right ladies golf clubs to put in your bag. Knowing your swing speeds and what the length of your clubs should be is fundamental in this process. Be aware that most people, both men and women, use clubs that are too long, and they do not use enough loft on the driver.