Personally, I think it would be a little out-of-place for you to try and redress this situation by saying your team leader is appreciated.
A team leader is a management role and is not only a senior position (actually they are not always ranked or paid higher in every organisation) but it is a different role requiring very different skills to those they supervise or manage.
To fulfil her role, your team leader should have the skills and experience to understand that feedback from employees is normal and not to be taken personally. A manager should see things from a "higher level" than those they manage and therefore does not need to be as "technical" or get involved with the work with the same level of detail. Really, they should be grateful for the feedback they get from their staff.
In fact, many organisations and managers believe in what is known as "360-degree feedback" - whereby feedback from subordinates is sought out, gathered and evaluated. So getting feedback from her team should be normal and useful. If she is a new manager, she may not yet have this skill or may not be used to receiving it.
Rather than try and correct what you perceive to be her taking offence, I would recommend that you leave it alone this time. It may allow your team leader some time to readdress their own management style. If they are not coping well with feedback, they are more likely to receive help for this from their own line manager. However, next time you give feedback you might want to choose your words more carefully in order to keep any criticism constructive and lessen the chance they will take it personally. For example you might prefix what you say with something like:
This is a really good idea, but how about...
That might work even better if...
Generally, feedback is most effective when it is direct, even if it is difficult to hear. Some managers attempt to "sandwich" what they feel may be perceived as "bad news" between two pieces of "good news". Others use what is known as "below the line discourse", which involves placing unpalatable information right at the end of a long discourse on other matters. These ways to deliver feedback are now widely considered to be bad practice. Really then, balance your desire not to offend your team leader with the importance of having your voice heard in the workplace and being able to make a difference to your working environment.